1994 - 2002 GM Truck Twitchy Erratic Crazy Fuel & Oil Gauge Needle Aircore Motor Repair (Chevy GMC)

This video goes over ONE possible cause for an erratic (crazy spinning needle) fuel gauge for old body style (OBS) GM trucks and vans of the 1990s and early 00s from Chevrolet, GMC, Holden, & Cadillac not working. In many cases the vibrating, twitching, bouncing, fluttering, and related unexpected jumpy behavior from the gauge has nothing to do with electrical grounds or the fuel tank sender, it is simply the effect of age on the aircore motor of the gauge itself. The original internal dampening effect is lost, corrosion sets in and the air core motor gauge becomes unreliable and must be replaced. Note that I said "aircore motor", there are NO stepper motors in these years!
The vehicle illustrated is an OBS (old body style) 1999 Chevrolet K1500 Suburban with the 6.5L diesel engine, but the symptoms and repair procedure apply to all GM trucks and vans of the same general era - before the introduction of stepper motors beginning in model year 2003. Of course the cluster disassembly I show is 96+ OBS only.
These motors were never sold by GM. NEW ones are in an OFF WHITE plastic housing color, whereas the originals were typically a yellow color. You have to pay attention to the calibration code letter in black on one of the housing ears as shown in the video. But DO NOT BUY USED yellow original ones - the air-core motor calibration is from a fluid internally that degrades with use and age so every original has the dampening defect to some degree as well as corrosion - so you'll be risking a failed repair by buying used. You can only fix the erratic behavior reliably by installing an (NOS) NEW air core motor OR a speedo shop remanufactured one. Each GM gauge type uses a different aircore motor calibration, so again please take note of the letter codes below!
Original calibration codes:
F = Fuel gauge (94-02 OBS trucks only)
C = Fuel gauge (1999-02 NewBS trucks only)
P = Oil Pressure gauge (94-02)
V = Voltage gauge (94-02)
S = Speedometer and Tachometer (94-02)
S = Transmission Temperature gauge (1999-02 NewBS trucks only)
T = Engine Temperature gauge (94-02).
If your fuel gauge needle was way off you will have to get access to a new fuel tank sender, hook it up and use it to calibrate the empty, 1/2, and full positions accurately. You can similarly re-calibrate major differences in the other gauges by replicating the source sensor input.
The eBay and Amazon search links below are paid links, for which I may be compensated and earn a commission, if you choose to buy the parts and tools shown in this video thru them:
Those still selling the "F" new - ebay.us/VqEbdY or ebay.us/nud8nD and one selling rebuilt - ebay.us/2SHX5a
All calibrations (skip over the yellow used ones unless they are rebuilt): ebay.us/OKZvii
C calibration: amzn.to/34OvXnD and the S calibration: amzn.to/3lLGBAS
GM 25089350 / ACDelco part number PC195 (replacement instrument cluster bulb) at eBay: ebay.us/nfUgt4
Alternatively Dorman has a complete remanufactured cluster for these trucks. Dorman 599-350 for auto & Dorman 599-460 for manual trans: ebay.us/HED3wc
Here's the GM service manual: ebay.us/2vlHP3
NOTE: It is very important you first eliminate a faulty fuel sender, bad grounds between your PCM and the fuel sender & the instrument panel. Your fuel sender is sending an analog signal to the PCM. The PCM is converting that to a digital square wave signal it sends to the cluster. The aircore motor for the fuel gauge is calibrated with a dampening fluid to smooth out the high and low points of this digital square wave signal. When that fluid degrades, the twitching begins. The gauge is otherwise accurate, until the aircore motor completely fails internally and then points off the gauge.
And if I've saved you some $$ here, consider some coins for the coffee tip-jar! ko-fi.com/drshock
Chapters:
0:00 - Problem overview
1:25 - Removing the IP cluster
8:32 - IP cluster disassembly / aircore motor removal
14:37 - Replacement aircore motor installation
22:59 - IP cluster adjustments and reinstallation
#drshock
Disclaimer: DrShock, the alias for the human content creator for this KZbin channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, vehicle whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate vehicle manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any vehicle.

[@DrShock]

PSA: Guys the supply of these replacement Air Core Motors seems to have dried up and they are much harder to find now. Several links here and in the video description text to help you though. Try all of the links on both eBay and Amazon to find the best price for the calibration(s) you need. They were available for a time as outfits like Dorman that were remanufacturing these dash clusters, as well as local speedometer repair shops, provided enough demand to warrant producing them still. But as of March 12, 2020 they are basically in the new old stock (NOS) stage now and every one of them will be an easter egg hunt. The "F" calibration is the hardest to obtain now, I see only two sellers on eBay affiliate linked below: One seller on eBay, USDashWorks, who is selling the actual units I have bought in the past, has them back in stock. They have a core charge now though and he's got the "F", "C", "P" "S", and "T" calibrations currently - ebay.us/VqEbdY. Here's another I found - ebay.us/nud8nD. Here's a third seller, selling refurbished "F" calibration air core motors - ebay.us/2SHX5a (remember anyone selling yellow plastic housing motors are selling used pulls or rebuilds, not NOS). I'll update this pin if the supply situation should change. Remember the used yellow original ones will not fix the needle dancing problem my video covers for the "F" or "C" fuel gauge air core motors, but the used yellow ones should be fine for the other gauges in "T" "V" "S" and "P" calibrations and to correct a completely inoperative / dead gauge situation.

[@Monuments_to_Good_Intentions]

DrShock I am going through a bunch of these 6.5 videos once again because my truck is broke down once again. I hate this truck. I really hope I can earn enough money to buy a new truck soon. Good video btw. If I cared about my truck, I would do this swap.

[@usdashworks4456]

I'd like to add that we have remanufactured "f" motors and they are good to go. I have the original applicator to inject oem fluid into the motor. The "f" motors are permanently out of production. The remanufactured F motors are the only option now. Visit www.usdashworks.com to place your order.

[@GeekBoy03]

I am having a different issue in my '94 Suburban. I can tell when the oil is getting low when the oil gauge starts twitching. I get low on oil quite often because I am using that special Mobile 1 0W-30 for better fuel economy. For the fuel gauge, I think it was not calibrated for the fuel tank. From the factory, it came with an optional 45 gallon tank. When the tank is full, the gauge goes way past the F line. The lower the gauge goes, the more accurate it becomes.

[@DrShock]

@@GeekBoy03 Past full line really sounds like a sender problem. This video might help - kzbin.info/www/bejne/mqiceZyXapqsr9U as the test it covers is for both gas and diesel.

[@pulpo.r7790]

If you can find new replacement, the white ones will work for fuel level? I went to the junkyard and found a F gauge. And it had good resistance so I replaced it but it still vibrates. I adjusted the gauge as follows. And I also replaced the fuel pump. Due to a fuel sensor level code. So I’m sure the fuel pump sending unit was bad and the gauge was bad as well.

[@km6344]

FINALLY!!! A video that not only is exactly the issue I have,, but also a step by step as you "show" the steps where there are no gaps where I have to guess or wonder any of the steps, like other how too videos on here! Thank you for this video! I was about to replace the expensive sending unit! I woulda benn so pissssed to find that wasn't it!!! thank you!

[@brandonstennes4931]

In the future when the next gauge in your truck goes crazy twitching. Try using super lube silicone oil, used that on my fuel gauge it was doing the same thing, twitching and going crazy. The fuel gauge works like a damn now.

[@arabcampers9554]

I had this fuel gauge problem in my 1999 suburban and its driving me crazy I did a lot of researches and many peoples were talking about changing the fuel pump clean the ground terminals taking the gauges out and clean it with alcohol its all worthless solutions , a close friend to me knows about me having this problem he sent me this video as Christmas gift I'm serious that was my Christmas gift and guess what its the best gift I ever got in my life because this video CLEARLY showing me the problem and how to fix it straight forward , Sir you saved me from getting rid of my 1999 rare Sony edition suburban .Thanks a lot and Merry Christmas .

[@DrShock]

That's great Merry Christmas! Here's another one, as sometimes this behavior can be the fuel sender too - kzbin.info/www/bejne/mqiceZyXapqsr9U

[@benkanobe7500]

None of us could ever be expected to be able to do this without your outstanding video! Thank you so much!

[@condeerogers5858]

Great video. You have helped a lot of people with this problem. I am one of them. Thank you.

[@randallsutton4168]

me too!

[@macgayver496]

Enjoy the coffee! Had to replace the gauge cluster stepper motors on my 2002 Buick LeSabre. The Buick's erratic oil pressure reading was just the sensor; same thing on my GMC. LeSabre fuel readings were the sending unit on fuel pump. Thanks for the videos.

[@MrBowNaxe]

Excellent video! I've watched it several times and feel confident I can finally fix my '99 Suburban after all. Thanks for sharing this video for all of us!

[@guillermobuenohernandez847]

I have a 1999 Chevrolet Tahoe and my fuel gauge is at full tank when I have a quarter tank ,. Thanks to this video I have the link so know I can buy this part for my cluster.

[@tarbeau8561]

DrShock, I too get to do this with my truck sir. But, thanks again for sharing your knowledge and videos, it won’t be as hard as I thought it was going to be. Thanks again for sharing your videos so we all can learn something about our trucks or SUV’s.

[@JoseMartinez-we1ux]

AWESOME! I have the same issue. Been trying to figure out what is wrong with my gas gauge for years. Thanks!

[@justwigs]

I HAD THE SAME PROBLEM A YEAR AGO REPLACED THE FUEL PUMP FIXED IT,ON 1998 GMC SIERRA EXTENDED PU 5.7L

[@paulking2279]

Thanks for the video! Definitely saved me some time! No more vibrating fuel gauge!

[@pup734]

I really find your videos on these trucks really helpful thank you

[@jameslewis1175]

Man u have the perfect voice for narrative informational videos. It's like it's easier to absorb knowledge fromya

[@camarokurt]

You saved me from pulling the tank on my Suburban. Thank you.

[@jaimerios995]

I have a 99 gas suburban. Did that fix your issue

[@makingtechsense126]

Great video! My fuel gauge is starting to develop this problem so now I know what to do to fix it.

[@WillCtheMechDrummer]

Great video bud!!!!!! I’ve done these before and just bought an old truck for myself. Needed a refresher… thanks! Subscribed!

[@denniswoods8894]

Thanks!! My 97 Yukon fuel gauge has the shakes!! Keep up the good work with the videos 💪🏾

[@justpaynmydues]

LOVE YOUR VIDEO! DECENT INFO ON PROBLEMZ WITH THE GUAGEZ! I RESPECT THE TYME YOO TOOK TO LET OTHERZ KNOW WHAT COULD BE WRONG. KEEP UP THE GOOD WERK!! 👏🏼👏🏼😁😁👍🏼

[@Twin_Flyer]

Excellent video, thanks for posting it and the link!!

[@chrisschultz6541]

Did this to my '99 tahoe. Seems to be working so far. Tip: fill your tank full before. Don't try and fit every single drop in your tank. Just go the the standard first click at the pump. When you first turn it on, the fuel gauge should adjust itself to full, it is slow. Let it go for a minute or 2. Key off, adjust needle and do it again. Run it with the cover off for a little while and watch your gauge, make sure it continues to read correctly. Go to 3/4 tank, fill up. Do the math for your tank size and it should be good. After you verify, close it all up. Gauge motor delivered was about $104.

[@franksteve5594]

Whereabouts did you purchase the gauge from?do you have part number?

[@PastorJack1957]

My 1996 gas fueled Tahoe has the same issue. I find it interesting a diesel would also have the same issue. Thanks for posting!

[@scout4locations]

Oh man, this was both hilarious ad informative. I just found a sealed and preserved GMC SUV cluster that hss a tach that goes to 6 whereas, my 1995 Yukon has one that goes only up to 5. So, I one found in a field out in the desert. The desert sands are used frequently by illegal trash people and the stolen vehicle mafia for parts dumping. It has sand inside it but I am still going to try it out. And here is shocking reason why: You see, I too am suffering from the painful and expensive disgrace of living with the embarrassment of having the insidious condition of The Fuel Gauge Twitch. Hiw much gas do I have left? Thats that little dials only purpose. To let me know that I could be stranded by you in 20 miles. Now I have to do the MGP math. Then remember my miles. Wow, fuel gauge, I never realized how much you really do for me. Thank you.

[@LetsFigureThisOut]

Just repaired my Safari using this video. Thanks

[@stebstebanesier6205]

Thank you, not only was this video very helpful, but for the most part it wasn't shot by you holding the camera in one hand while trying to do the repair with the other hand. So kudos to your camera person, and i wont even discuss video that are shot vertically.

[@ronmiller682]

Thank you for sharing your knowledge, this is exactly what needs to be done to my 98 truck and dads 99 tahoe.

[@BigWheel.]

Thanks for the video! I just bought a 97 yukon GT two door, and the fuel and oil gauges fluctuate. Hopefully now I'll get it sorted.

[@juanreynoso9653]

Thank you I enjoy the video very much I totally appreciate what you've done.

[@KYoss68]

Temp gauge pegged itself at 260 the other day but the engine didn't seem unduly hot. Will investigate further but I bet it's going to be this. Thanks for the comprehensive video.

[@johnk7050]

Perfect! Yukon getting and trying to keep together because I still like it. Was able to do with your video help. Thank you.

[@shawnswnh1054]

Wow glad I found this video, my 1999 suburban fuel gauge is doing the same thing, I was dreading dropping the 42 gallon tank but will try this first.

[@david206820071]

Just finished my part now next step will be installing everything back and see it working back to normal

[@adamx6186]

Holy crap, no wonder my new fuel motor didn't work, I missed the crucial step of swapping over that tiny resister from the old motor. Too bad I had already thrown it away, but luckily I had just bought a parts cluster cheap for the temperature motor. Great video! Thanks

[@MrJdub20tx]

My temp Guage is acting funky too I changed both sensors already too

[@irredeemabledeplorable5227]

Informative video...thanks...I only wish people would check their volume when producing these vids...We can ALWAYS turn it down if it's too loud...lmao

[@poncetorres7110]

Grate video nice thank you for sharing. ☺👍🏻.

[@apsonyo2407]

Great video hope other people learn that you need a camera person to do this kinds of video and not trying to do everything with one hand love it I think I can take on my own instrument cluster thnx

[@theon_ean_donly]

Wow never expected to find this video thank you so much blessing 😊

[@bucksmith9035]

ive got an astrovan does the same gauge fluctuation was told sending unit in tank now ill replace this unit first thanks for this video

[@snickerstorino]

gm has a great reputation for faulty dash and electrical issues in the 90's and early 00's. just an fyi if the oil pressure sensor goes out in yours depending on if it shorts or loses connections it can peg or show zero. zero return reference from the sensor in my 92 causes it to peg out, just some food for thought. if the sensor in my 92 actually sends a zero signal it kills the fuel pump. i recently had it go bad and for a year it was pegged. replaced the sensor and away i went with finding other things that were bad too. This said one wire on my 92 goes through the fuel pump relay and back to the pcm, one of those is a fuseable link so if its damaged that can screw with readings too. Best thing to do pull the sensor and check the pressure manually, this will tell you if the gauge or wiring is the issue. If the oil pump really is bad and the sensor is working it will kill power to the fuel pump. If the cluster is screwing up it will still throw the check gauges but will never kill the engine.

[@DrShock]

Thanks, good points. FYI that GM safety design ended in 1995. The oil pressure sender from 96+ is no longer involved in the fuel lift pump circuit.

[@snickerstorino]

@@DrShock interesting, I didn't know that but thanks for the info. I just wanted to share my recent experience with my 92. I had a 99 suburban with dash and fuel pump issues but the pump had power so it was a no brainier and the cluster has shitty grounds everywhere.

[@snickerstorino]

@@DrShock you wouldn't happen to know if these are the same motors in my 92 would you? i think the motor is weak, the oil pressure is different than the gauge according to my manual gauge i hooked up. it also doesn't come up with rpm increase sometimes but does other times and other times it drops to zero after its hot and then when i restart it goes higher but slowly drops back to zero. i suspect the motor is weak because it was pegged out for a while when the sensor was shot. i haven't torn it apart but i wondered if it was, thats actually what brought me to your videp

[@DrShock]

It's going to be the same aircore type gauge design, but I do not know if it's the same part used on the later models or not. Even the ones I did this video have had their supply dry up during the pandemic though. I pinned a comment at the top of a speedo shop on eBay that offers a rebuild service. You might ask those folks.

[@snickerstorino]

@@DrShock thanks, i appreciate your time.the salvage yard has a cluster so i might try my luck there. hoping my amazon oil pressure tester is right, i don't want to do an oil pump. the gauge is acting a bit strange, my only concern is when the gauge hits 0 oil the check gauges comes on but if i manually push it over it doesn't trigger the same warning. so i don't know if the gauge triggers that or the switch itself. not sure exactly how those operate but i will put this other cluster in and see what changes then swap the motor if thats it and keep the rest for future use if the motors are all gone. the yard only wants 50 for the whole cluster but who knows whats good in them. again thanks alot for your responses

[@jorgefonseca9225]

great vedeo mate you save me a lot money great explain!! cheers from norway

[@brettpresser2256]

Very well done video it was extremely helpful

[@JorgeTorres-lj6dt]

Fantastic buddy thanks for your help

[@bobcormier5098]

Good job bud......now I no wuts going on with my fuel gauge it flickers here and there .....I have 1997 gmc savana van. But it says gmc truck on the van. But verrrry helpful thank you

[@nonameisthename138]

WOW!! I wasn't looking for this video, but my RPM needle has just started to do this occasionally on my 92 Silverado. Thank you, and great job!! I know what to do for it now..👍

[@josepalacios9020]

Thanks man great video

[@fulgenciomarcos9350]

Finally I found what I need. Thank you.

[@hermthegerm4039]

Great info thanks very much

[@allentuggle6732]

I appreciate you looking at your video and coming back to clarify.

[@cheezblock4lllll]

ive looked everywhere for the tool u use to take the needles off cant find it anywhere must be a rare tool lol good vid thanks for the walk through. good info

[@DrShock]

Yeah super rare to have one clean for this application, if you mean at 12:33 it is the highly useful forkomatic from Chick-Fil-A. ;-)

[@mikehuff7294]

Thank you! Very very helpful

[@SimonTekConley]

I just learned the truck had a cup holder.

[@billstonesmith9231]

Great job Dr Shock!

[@lambertsaldi1550]

Awesome Review thank you 👍 🇺🇲

[@1deadpool11]

Good man. Thanks for the info

[@redlightrunner930]

Well off to the internet to get new guages. Good video.

[@CDSAutomotiveGarage]

Yep I have a 98 Chevy Cheyenne 2500 5.7 and does this . My oil pressure gauge seems to work but my oil pressure isn't good when gets hot but my temp is off and my gas gauge is off

[@justfixit9726]

My gas gauge spun like a clock and just like you said it took out the oil pressure gauge. 99 k1500 5.7 suburban. Its a shame it went bad altho i had to replace the stepper motors in my 04 yukon 2 years ago. So it lasted longer (suburban) then the next generation factory replacement(yukon).

[@ezequielpena5492]

Man I’m glad I found this video!! I have the same problem on a 1999 suburban!! I’m going to order parts to get her fixed

[@jaimerios995]

Did it fix your issue

[@jaycrawford6498]

I have a 1993 Chevy diesel. Is it pretty much the same procedure. Also are the parts the same.

[@marioc.bitanga1974]

Great video awesome ....information now I can order my voltmeter air core n c if it will fix my discharging problem

[@jimmytorres111]

Great video

[@nafeesahmad9761]

Good information 👍🏼

[@donaldlong9649]

thank you

[@Abdullah-Alamoudi]

Very helpful video. Great job. THANK YOU SO MUCH.

[@jmacedo7]

Dr. Shock como siempre muy buenos vídeos tutoriales, específicos y educativos. Quería hacerle una pregunta muy específica al tema: Resulta ser que hace unos días desarme el panel de instrumentos de mi tablero del coche. Para remplazar unos Light bulb fui muy cuidadoso aproveche para limpiar instrument cluster connector tanto en macho como la hembra con un cotton tip y alcohol isopropílico (ya que veían con algo sucios y con polvo). Antes de volver a montar instrument cluster; Después hice mis pruebas abrí la llave ignición todas sus luces bien, gauges bien, selector de cambios prnd123 bien. Y al cerrar la llave de encendido. Probar la iluminación, encendido los tail light Hooo! Sorpresa 😭. El gauges del oil y fuel se mueven a la posición cero más que nada el del oil y si enciendo el motor y Luego tail light veo como el medidor se mueve una un poco hacia cero o empty pero como la señal del ops o fuel sender unit son más fuertes pues no se va a 0 psi. Buscando información en internet me topé con tu vídeo kzbin.info/www/bejne/mqiceZyXapqsr9U. El cual me ayudó mucho vi instrument cluster connector en esos diagramas pude identificar cada pin (porcierto que libro usas, ya que aquí en México no es fácil encontrar esa información) Me topé que el pin 29 es el de las iluminación dimming del señal tail light y hay 2 ground el pin4 que es para la electrónica del cluster y el pin 31 que es para bulb light y Gnd de los gauges veo que se comparten. Use mi multímetro para medir resistencia y noto que midiendo el pin 4 a cualquier metal expuesto e la carrocería hay una resistencia de 20 ohms yo deduzco que a de ser la vejez de cable pues 22años. Pero yo le pregunto sabe usted si el Gnd del cluster tiene alguna resistencia de paso como protección. O va directamente al chassis y si para estos cluster es despreciable eso 20ohms en el conductor o recomienda reemplazarlo el cable para bajarlo a menos

[@DrShock]

Mucha información aquí, intentaré abordar la que tienes. - Debe tener cuidado con los solventes en una placa de circuito impreso de mylar flexible como la que se usa en el grupo de instrumentos. Puede dañar el plástico en algunas formulaciones. - Sí, las bombillas de repuesto de la marca del mercado de accesorios pueden tener problemas para hacer contacto con la placa de circuito impreso flexible. Puede levantar, ligeramente, las clavijas de contacto de los portalámparas con cierre giratorio. - Estoy usando el manual de servicio de camiones GM genuino de 1998, que ha estado agotado durante más de una década. - No estoy familiarizado con todos los circuitos de tierra involucrados en el esquema del grupo de instrumentos. Pero suena como un problema de fondo que está describiendo allí. A lot of info here, I’ll try and address what you have. - You have to be careful with solvents on a flexible mylar printed circuit board like that used on the instrument cluster. It can damage the plastic in some formulations. - Yes, aftermarket brand replacement bulbs can have trouble making contact on the flexible printed circuit board. You can pry up, slightly, the contact pins on the twist lock bulb holders. - I’m using the genuine GM truck service manual for 1998, which has been out of print for over a decade now. - I’m not familiar with all of the ground circuits involved in the instrument cluster schematic. But it does sound like a ground problem you are describing there.

[@jmacedo7]

@@DrShock muchas gracias Dr. Shock , no sabe cómo. El manual de reparación de la GM que tiene se le puede comparar con libro CHILTON 28624, o nada que ver el original siempre será más completo??? Para concluir podría hacerme un favor : en su otro vídeo muestra en su manual GM en la hoja del : "instrument cluster connector" Que el pin 4 y 31 que comparten Gnd menciona que revise el circuito N° 451 de su libro. Agradecería si me mencionara si el cable va directo y atornillado alguna parte metálica carrocería o chasis y porque área aproximadamente se puede encontrar esa conexión en la cabina o si pasa por algún circuito de protección y por eso la pequeña resistencia. Dr. Shock de lo demás yo me encargaría e investigaría. De antemano gracias.

[@DrShock]

He utilizado guías de Chilton para vehículos en los que no tengo el manual de GM a mano. Ciertamente son buenos libros y los recomendaría. Pero no puedo decir si la camioneta de este año tiene lo que está buscando esquemáticamente. No he tenido que depurar el circuito de tierra del grupo de instrumentos, así que no puedo decirlo. Pero conecte a tierra cualquier circuito de tierra 4xx (por ejemplo, 451) que se ubicará en el área de la caja de la rueda trasera / cama. I have used Chilton guides for vehicles where I don’t have the GM manual handy. They are certainly good books and I would recommend them. But I can’t say whether the one for this year truck has what you’re looking for schematic wise. I haven’t had to debug the instrument cluster ground circuit, so couldn’t say. But ground any 4xx ground circuit (e.g., 451) is going to be located in the rear wheel house/bed area.

[@MaryRaborn]

Yess!! My oil gauge does this andy fuel as well!! It causes it to pop up a check gauges light and causes it to idle.rough

[@DrShock]

If you're getting a service engine light, it's not the gauge but rather a genuine engine issue you need to get diagnosed.

[@colorblind1983]

The gauges and the trip on my 96 Tahoe are messed up too. According to the instrument cluster, my truck runs super cold, and I always have a full tank, except when I decelerate with about 1/4 of a tank.

[@Bingo551]

Wow! that's exactly what's wrong with my fuel gauge. Thank you save me possible 500 to a grand.

[@bobbiesawada9460]

@the section about the bulbs , these are all 194's? I assume these are clear bulbs wondering if I decided to use maybe blue if it would affect the orange needles..

[@DrShock]

No, not all of these are 194s. Some are different, see 6:53

[@mtebaldi1]

Wow, You have some great oil pressure on that 6.5L.. Must be really low mileage. My 6.5 is 195K and only puts out 25 at idle and north of 35 almost 40 when running down the road.

[@scottloftin1730]

Thank you!!!

[@JM-yx1lm]

Good thing you told us how to do the fuel gauge, cause that's the one you didn't say how to do other than to remember where it was but that kinda no help because it's erratic and who knows if its actually sitting at whatever. What if the gauge doesn't work? I guess I could fill the thing plum full probably be the only way.

[@darrindemay7079]

I was going to buy one of these aircore motors on eBay, as suggested, and found one being offered by Digital Dash Solutions. Out of curiosity I Googled them, found their website, and saw that they were offering the same aircore motor that they're selling on eBay for less money, $30 instead of $44! So I ordered one from them, received it in California from Connecticut in a couple of days, and I just installed it yesterday. My old one had been doing the quivering thing and occasionally swinging wildly, then it would stay on "Full", so I couldn't mark the level as shown in the video. So I went and filled the tank, then set the needle on "Full". Now I'm going to have to drive around and see if the needle responds the way that it's supposed to...

[@chanceb4195]

Darrin De May did it work out for you?

[@jonatanreisin3647]

Excelent video and explanation. Could you give me some advice to check why the PRNDL lights indicador doesn´t work. Thanks

[@DrShock]

On these years PRNDL part of the instrument cluster is fed range input by the park/neutral position transmission switch. I've not encountered this sort of issue before on the 90s trucks, but I would hazard a guess it could be a problem within that specific switch, or a problem getting voltage to the PRNDL circuitry of the cluster. You would have to get the service manual schematic and check each of the 4 switch outputs are making it to the IP cluster connector, then check that the lines for PRNDL voltage/dimming are making it. If those are good, it's a problem on the IP cluster circuit board itself.

[@jacobmahy5704]

It probably your neutral safety switch located on the trans mission

[@nicky9148]

Same issue..my gas gauge jumps from full to empty..I have just been making sure I keep it full at all times

[@jamesm568]

At least now I know how to get to the little light bulb for the P R N D 3 2 1 indicator.

[@bruzavich5242]

Thank you

[@emiliojrgobea6490]

Nice job

[@marktieman7022]

Very detailed movie love it

[@davidjones7423]

I have a 2000 obs 1ton classic My fuel gauge reads about half when it's a full tank. When the key is off it zeros out. Your video shows it doesn't go to zero/empty with the key off. I'm trying to re calibrate it too read full. I have a full tank now.

[@Mr2004MCSS]

Nice video. I have two 98 chevrolet trucks. The half ton's gas gauge does not work and it usually reads completely full no matter how much gas is in it but will periodically drop down to empty and then go back to full. The needle also has a slight vibration to it so that it looks blurry when you look at it. I don't know if this is a sender issue, wiring issue or the gauge. The 1 ton's oil pressure gauge bounces around and always reads 80 psi initially. The volt gauge usually always reads low and my speedometer is off by about 5 mph. I would like to fix all of these issues but those motors are expensive so I may just have to live with bad gauges.

[@DrShock]

Thanks, the fuel gauge needle twitching/vibration is definitely the aircore motor itself and the subject of this video. But the gauge not working reliably, or at all, is more likely the sender in the tank. This other video I did was mainly for the diesel engine but the schematics and test process in the front are the same for gasoline. You might try this - kzbin.info/www/bejne/mqiceZyXapqsr9U Since you have troubles with the fuel, oil pressure, speedometer and voltage gauges it's more likely a cluster issue than all of those individual aircore motors going out at once. If this were my situation, I would try an LKQ salvage yard and pull an used replacement cluster myself, keeping the gauges but transferring over the odometer from my original and seeing if I get better results.

[@Mr2004MCSS]

@@DrShock Thanks for the reply and information. I will have to see if any of the salvage yards still have any clusters. The one ton truck with all of the cluster issues only has 119,000 miles on it .

[@addamochs]

Now I know how to disable the ABS light and service 4wd light. No front half shafts or drive shaft. Pulled the ABS fuse because I almost ran into the house because the ABS decided to wig out on me on dry pavement.

[@justfixit9726]

Normally the only issues with abs on these trucks is the front hub sensors. The hub rusts and the sensor is a magnet. So it flakes off and sticks to the sensor. If there seized in there just buy new ones if not pull them out clean off the crap and plug your fuse back in.

[@lionelwilliams9222]

Thanks problem solved!

[@17buckrogers]

nice job

[@TheTferrer]

Enjoyed this video. Have you thought about going digital instead of analog? Had the same issue with my vehicle then decided to replace the gauges with digital.

[@DrShock]

Nah, I prefer the OEM analog look myself.

[@greddmyles3677]

OK what about this, my fuel hand was going crazy so i changed the sending unit. I emptied all of the old gas out put ten worth in the tank start it up then the hand was like over from the E a bit, before I cut it off I noticed it was on F, and stayed there. So where do I put the needle when I fix it?

[@waltercardenas7354]

Outstanding Video. Are all the gages for these models 1994 - 2002 GM ?

[@DrShock]

While the video is specific to the old body style (ended in 1999 for pick ups, 2000 for SUVs, and 2002 for 3500 commercial chassis cabs) C/K truck models, the same type of aircore motors were used on the G van, P van, and S/T trucks as well. They were used on the first couple of years of the new body style trucks as well.

[@tonypadilla6404]

Thank you I have the problem and You did a Very good, I was looking for a good Video How DIY. By any chance how much do they cost

[@DrShock]

There's an eBay search link in the description, the fuel gauge version of the motor runs around $40 depending on who you buy it from

[@bobbiesawada9460]

I hope that I can find these motors, going to replace the factory radio while I have the bezel off , it still has the factory AM/FM Delco radio.. Any help locating these motors would be a help.

[@DrShock]

Supply from China has dried up. Pinned comment has the only source, an eBay seller, left who has some stock and original equipment to refurbish used motors as well.

[@angelhelp777]

First I wish to thank you for doing such a clear and detailed video. I have a few questions. At the 10:15 minute mark, you said that the fuel gauge will stay in its correct position when the power is turned off. My fuel pump quit working a few weeks ago and kept blowing fuses. When I changed the sending unit the wires on it were all melted and fused together. (I am lucky I didn't blow up.) After replacing the fuel sender my fuel gauge has been spinning wildly and jamming against the oil pressure gauge or stopping at random positions, so marking the position would not help since the needle always stops in a random position. Other than draining the gas tank to empty do you know a better way to find the correct position for the gauge needle? (Your video also showed me how to pull the dash so I can change all my burned-out lights...THANKS!)

[@DrShock]

Thanks, there's some more technical info in the video description too. But in this situation you have to manually recalibrate for empty and full. The easiest to do is full, as empty isn't really empty to help you get to a station you have some _reserve capacity_ even when it says E. So I would go for F instead, to start loosely install the needle, and fill her up. Then set the needle to where you usually saw the needle when doing a fill up (some will be slightly past F, some right on the money, and some a little ahead).

[@ypcomchic]

If they melted you may have a ground that is loose. Check all your grounds.

[@TheMcdrewb]

My 96 Yukon 5.7 goes “crazy” my 95 sub 6.5 isn’t far behind....this will help...oh look you have buttons to the right of the ignition(keys) thanks DrShock! Really like and value your videos...currently no pwr locks, pwr seat, aux pwr(cig) fuses seem good...I think it’s a ground...anyone know where that is? My A/c may have fried something....it stopped working (I cleaned the blower switch copper plates....it worked again(May have been wire movement) I think /hope it’s a ground wire

[@DrShock]

If all those options are out but fuses are all good, and the rest of the vehicle electronics and engine are functional then yes it could very likely be a ground problem. Very time consuming to track down such electrical problems, but I'd say having that much out you're looking for common ground and power routing as a start.

[@TheMcdrewb]

DrShock yep...Wish me luck! Thanks again

[@WillCtheMechDrummer]

A tip for those with a scanner that reads live engine and sensor data… including fuel level. I always connect my scanner with the cluster lens off so the needles are easily accessible. I watch the readings on my scanner versus what the cluster reads. If it reads a bit off, I shut off the vehicle and adjust the needles accordingly. I even test drive it to be sure the speedo is accurate. I hope this helps someone.

[@jamesharrison6201]

My 98 with the 4.3 is doing the same thing. Though when driving, the oil pressure settles down to 60.

[@tubehound69]

20:40 How many people have gotten to this point and then screamed, "But it's the resistor pack that's gone bad!!!"

[@davidmccary478]

I looked online for the stepper motor/ air core motors, and they are fairly expensive. to get a Dorman replacement seems like it’d be more cost-effective because there is all new parts and motors. I don’t have an erratic fuel gauge, but it is does vibrate. My issue is one of the stepper motors or something related to the speedometer is making a clicking noise at speeds 40mph and above. Can a person take it apart and blow canned air around the motors to blow off any contamination or dust that might have accumulated throughout the years that might cause erratic needles or noises?

[@DrShock]

Air core motors are totally different than stepper motors. Air cores are way old, all the way back to the 1940s. But the most common condition that this video points out is that the ones GM used have an internal dampening fluid, it's way dried out after over a quarter century on these trucks now. So replacement is the _only_ repair. There's nothing mechanical with the speedometer gauge on these trucks (also air core based so no mechanics just electromagnetics). But clicking noise coming from the speedometer gauge area might be related to the odometer which is mechanical. Could be a nylon gear lost a tooth or such there. It could be generated from other mechanical components in the same vicinity too (e.g., cruise control module on the other side of the firewall, fuel line vibration against the firewall directly opposite, etc).

[@davidmccary478]

@@DrShock ok thank you so much. You are awesome mine is a 98 Chevy Silverado pick up. I do think the gas gauge is going to go out anytime because it’s been vibrating forever. As far as the noise goes I said clicking but I also think it might sound like a rattling and it’s related to the frequency of speed going 40 mph and above. If it is a gear assembly in the instrument cluster do you think blowing the gearing out with canned air might resolve the issue?

[@DrShock]

If it's a broken gear tooth causing the noise, no because a cleaning won't effect any sort of repair. If it were somehow some sort of debris lodged in the mechanism, possibly. But in this situation there would be some interruption of function, either the trip meter or odometer no longer functioning properly or the speedometer no longer functioning. Much more likely to be coming from somewhere else imo, but you would have to pull the cluster and inspect it more closely.

[@davidmccary478]

ok thanks a bunch i appreciate the help. have a great day

[@mikecooper2732]

Where would one find those clips that you made some adjustments on?

[@DrShock]

If you're talking about the clips that retain the aircore motor prongs into the cluster housing/circuit board, only from a salvage yard donor vehicle. If by chance you're referring to the resistor pack that clips onto the back, you only need to worry about that if your aircore motor had one originally and you just transfer it over.

[@JasonTylerRicci]

My 2000 Silverado gas gauge isn't twitchy. One min it's on empty, the next it'll jump to full (just filled tank). I fill tank, it's still on empty, then a few mins later, it jumps to full. This goes on and on. Now it seems to be stuck on full, even after driving 95 miles. Stepper/aircore motor? Sending unit?

[@DrShock]

2000 Silverado would be stepper motors not aircores, totally different tech. When I replaced the stepper motors in a 2004 it was because one of them had gotten to where it was upside down and off the scale. I've seen other symptoms where they just get stuck. So it could be your stepper motor, probably other videos that dive into diagnosing that more specifically. Could be just bad grounding though in the sending unit harness path.

[@German_MDS]

Nice video. I'm looking at ebay and there are no more "F" aircore motors available. They are selling the "C" for the fuel. Any idea if those will work? Thanks.

[@DrShock]

The most sensitive is the fuel gauge, because it's the one that actually has a dampening calibration needed to avoid the whole problem this video is about (which is caused by how the PCM sends its fuel sender signal). I would only use an "F" as originally spec'd by GM for the earlier model years. The "C" is for a later cluster. I have another truck that I need to do this same repair on for someone, and I wrote to one seller, digital-dash-solutions, who should have more "F" aircores in stock in a few weeks. I'm going to wait for the right part myself.

[@German_MDS]

@@DrShock Thanks for the reply. I asked the same seller cause he is offering the "C1" for fuel. I'll be waiting too. Thanks.

[@vinosfinostapasandwinebar5109]

How many 194 bulbs are replaceable? Want to install LEDs. Pleas advise. I have changed two motors. Great video.

[@DrShock]

Some of these are PC195 bulbs, there's a link in the description for them. The difference is that the bulb and socket are an integral part, rather than the bulb being separately replaceable. Once you see what they look like, you may be able to find an LED equivalent.

[@bobbiesawada9460]

I have a 1995 Chevy S10, the oil pressure gauge seems to go crazy and give odd readings and my tachometer needle stops at 1000rpm when I turn off the engine. I can tap the cover and the needle goes back to 0. Is it a air core issue?

[@DrShock]

If tapping on the cluster lens affects the needle position, then very possibly. This problem is typically a fuel gauge only problem, so I wouldn't immediately jump to this as the cause of incorrect oil pressure readings or the tach without further debug and analysis. But if the needle is affected by "tapping the glass" that certainly sounds like a problem with the motor to me, perhaps in conjunction with something else though you may still have to diagnose separately.

[@laredo1307]

I have a bouncing fuel gauge that I assume has to do with a broken slosh baffle in the tank. I haven't checked to confirm but now I'm wondering if it's the same cause as this one.

[@bobcantrell2628]

Where can you find these at I am not finding them