how to test wire troubleshoot GM headlight switch

[@benjaminredington2905]

Everything anyone needs to know about these. I finally know why marker lights go out when headlights are tuned on, (and how to change it). Thank you for doing such an educational video. Well done.

[@briizcustoms9543]

I’m having marker light problems, why?

[@Adel_Volks]

How did you fix it? Did you replace it?

[@mikeminor3478]

Thanks for posting. Couldn’t and wouldn’t have been able to get my hard to source 63 Lemans switch working without your knowledge. Thanks

[@SubePelayo928]

The “G” tab is for the cab dome light. The orange wire that comes from the fuse panel also splits off from the fuse panel to a dome light. So when you ground the switch out by rotating it. It activates the dome light

[@hydrocarbon82]

Thanks for the comprehensive vid! All the other vids were useless. Thanks to this, I rebuilt my switch and figured out all the interior light issues. You also gave the only correct wire color info I could find.

[@DaveFormulaGTO]

This video just helped me take my switch apart and get my tail lights working again. Major thank you.

[@blakeminor2881]

I’ve been having issues figuring out fixing a dash light problem. Thanks for the awesome video.

[@billw577]

Thanks for posting this! Working on some wiring on my '32 Chevy and this helped me figure out where the dash gauge lighting wire should be coming from. I also had to order a new switch because the ohm readings were all over the place.

[@sasquatchhunter5802]

Wow! It took a lot of work to but this video together. THANK YOU for going to this level of detail. It really helped me with troubleshooting my switch.

[@tommyfernandez8344]

Possibly the best video I seen ever!

[@curtisballer688]

If more people did videos like this we’d all be mechanics!! One of the first 15 min videos worth watching! Nice job man !! Subscribed!

[@MrJobcon]

Im a big fan of your videos, you are excellent at explaining and illustrating how these parts work. Thank you!

[@brettslater872]

Thanks for making this. I refreshed two switches today - a 7 and an 8 tab.

[@ronvandorin2937]

Thanks, for going through the whole switch. Now I know how to troubleshoot the complete light switch. Keep the videos comming!!!!!!!!

[@Bob-Sacamano]

Holy shit I spent way too much time diagnosing why my front park lights would not come on and it turns out the PO installed a 7 pin switch instead of an 8 pin. THANK YOU!

[@lifestylemodificatio]

an 8 pin with the number 7 on it is a purple wire for front parking lights. thanks for all your vids chris 👍

[@adjiii]

Thanks! Great video! Been having issues with the lights in my '66 Skylark. Will bench test tomorrow.

[@9011combo]

I always re-watch your video, just to refresh my mind, thank you

[@par4n1]

Wow this is exactly what I was looking for. Im retro fitting my vaccume hideaway headlights to electric and useing this switch to open and close the doors. Thanks

[@outgoingcare]

The headlight knob can come loose from the triangular shaft. Mine is now epoxied together. The resistance wire usually breaks at the first loop. It may be possible to loop the second winding back over the first, it will work for a while.

[@TennesseeVdub]

Great Video Chris. Going to start there troubleshooting my 72 olds cutlass supreme. Headlights come on but no dash lights or parking lights

[@Wolf-cd5ij]

I just got a 71 with the same problem, did you ever find a solution? I have changed the fuses, the bulbs, and the h/l switch... No luck so far.

[@DAUltimateSACRIFICE]

Same problem here on my 72 buick GS.. I was told if you use a test light and pull the rod on the 1st stage its suppose to distribute power.. but if no wires except the red has power then the switch is bad then the 2nd pull of the rod.. the blue wire (headlights) will have power

[@toomuchtruth]

Extremely helpful video, appreciate the detail and how you opened it up and showed us how it works. Im trying to fix my car's headlights and dodge shelling out for new parts. Thanks a million.

[@chriscraft77022]

those switches usually always work, but the resisted spring sometimes stops working correctly.. thats why i made the video.. because once i started going through my car i realized that switch was not as simple as "people" say it is

[@jeff6645]

Great video, was able to test my switch and find my problem.

[@shuvl82]

Thanks! This was a huge help re-wiring my 55 Chevy

[@dedricbullock5567]

THANK YOU THANK YOU THANK YOU man this has been driving me crazy.

[@Iron_Thunderstorm]

VERY helpful. Have a 64 Impala that lost tail lights, blew a fuse so I jumped with a wire with alligator clips to it get home, the jumper wire got HOT and started smelling burnt! I'm deciding to replace the switch unless I test it and am able to clean up the poor connections until functional again

[@lindadecarmine5656]

I checked for number 7 pin then realized when I put new harness in, it only has 7 the switch I had installed already was an 8 so I swapped it out took it apart like your video thanks for the lesson.

[@rcjoslin]

Great video, thank you. Exactly what I was looking for.

[@rickbee5588]

excellent video. Was able to rebuild mine while I watched. Much thanks.

[@GTGTO-su8bp]

Update.... the switch was bad. Must be all the gunk internally. To save taking it apart I bought a new "clean" switch. 😊 Thanks Chris for sharing your knowledge. You have to get back here more often. 😉

[@hookem6387]

Love the videos Chris..question. I have a 1967 chevelle. I just installed an AAW wiring harness. Car starts and runs. Lights work. But when I turn on lights blinkers go out. Turn lights off. Blinkers work. Tried 2 switches and same thing. Suggestions please..???

[@scooterdon8365]

Proper ... Seriously. Well done and just what I needed

[@arizamirely2904]

hola hermano puedes hacer un video de como se prueba el switch o interruptor de luces de ford mustang 1984 y tambien explicar y mostrar la fusilera del mismo mustang donde se vea cuales son realmente los fusiles que debe llevar, me parece muy buen video muy eplicativo y facil de entender felicidades y espero que leas tus msj y nos responas a tus seguidores, saludos y exitos con tu canal espero el video de todo lo que te pedi que nos enseñes a chequear.

[@jamesritter]

Great video. Thanks for posting! :)

[@justinluscomb2305]

Great job explaining ur the king

[@willwarren304]

if the horn relay is bad would it cause the light switch not to work since number 1 is wired to horn?

[@Mel-Family]

Fantastic video man!

[@emorywalker9097]

Great job.

[@wertbe1718]

This video was very helpful, thank you so much!

[@RL-bu2ln]

awesome video. so the number 2 terminal is the one that stays hot in trying to splice the wire to light a eletric gauge

[@thomasrizzi1470]

Very well explained. Thanks

[@ogdon7518]

Awesome video. Just wish I knew how to remove the switch out a 1970 Cadillac Deville :-)

[@danielschrom5179]

Helped me find my problem thank you

[@bradleyslone2470]

Helped me to find out which terminal is the dimmer, thanks.

[@Directconnection05]

Hey! Hope you can get back with me!! Been having headlight issues for months now. Got a new dimmer switch and headlight switch and still having the same problem on my 87 Chevy 4x4. Power from the yellow wire going to the dimmer switch cuts in and out all the time. Stops getting power to the dimmer switch. Please help!!!

[@michaelcalderon4401]

How did you power up the switch to text it on the bench? Also when your ground the switch with the aligator clip what is that grounded to? Is it

[@teabag402]

Same question I had. He used a car battery

[@dougnacejr1600]

Thank you your video helped alot

[@GATOXXL69]

NIce Video! The "What-ever-the-hell-this-thing-is" (LOL) looks like a circuit breaker.

[@chriscraft77022]

its a thermal switch that is also a breaker like you said if it gets too hot

[@steveretiredandcranky]

Excellent video. Thanks.

[@davehottenstein5315]

I'm having a problem with 12v going out to the park and rear running light terminals I'm only getting. .6volts 2 brand new switches.. headlights come on and work but no park tail.. ground issue? 47 kb-5 with a American autowire 9 circuit kit.

[@JMcPheeters72]

Dud you are the shit you are a life saver I’m a hands on type of person I suck at wire p&ids

[@Mcheal2474]

Question my dash lights dont come on my idiot lights do n head lights m tail lights all good but wondered if my rheostat be bad cause my dash lights not to work . New bulbs n good connections so thinking of new switch would help . Gonna take it out here soon n check like you did n your video n if dont work then thatshould be my problem. Right?? Great video man !❤

[@pedroaguerrevere9118]

Thank you. Very Nice video

[@robkeller3431]

Purchased an nos switch for my 57 chev pickup. The knob won't ground to activate the dome light. If you know of a solution for that, please let me know. It Grounds by turning the knob counter clockwise. So much for nos..

[@johnwinden8511]

Good job, thanks!

[@GJJC13]

Great video. If you would like to bypass the dimmer, would you just connect together the 2 contacts you where using when you were showing how to test the rheostat? I am asking because in my car, even with the knob all the way to the left, the dash is still dim. Any suggestions? Thanks!

[@chriscraft77022]

I would get a new switch if it does that

[@JohnnyMacalvee-cf7et]

+Chris Craft, if I turn the switch all the way to the left, will it not drain the battery? I have a 70 GTO. You also state if I turn it all the way to the right it breaks the resistance. Which is better turning it all the way to the left or the right? I don't have the dome light working...so that adds to the confusion. Work in progress, but I am just trying to save my battery.

[@chriscraft77022]

put it to the the right

[@8up007]

Good video brother!!

[@curtisballer688]

What does a guy take to #G? It the the only terminal that’s not part of plug..ground assuming

[@chriscraft77022]

I got the c30 project started I will go over it again soon .. thanks

[@lifestylemodificatio]

another great vid chris

[@brandonhavely7465]

I have a 85 10 dash lights work but headlights don’t come on

[@BrittishCats]

Thanks! Helped me alot! 👌

[@4x4dually]

"And we are gonna grease this all up.....with some sort of....I don't know.....dielectric grease or shit...." LMAO

[@chriscraft77022]

i used to drink in my early videos and i thought it was cool to act ignorant.. i did go back and watch that and i thought it was funny.. i ended up greasing that switch with the dielectric grease and it has been on my car since the video.. some people claim they cant buy a switch for their vehicle.. i dont act like that in real life, though LOL

[@4x4dually]

@@chriscraft77022 I did appreciate the video. I have that same switch that I will take apart tonight so it was very helpful to see it. I liked the humor. If you haven't watched any of user "Ave"s video....you should. He is funny as hell and I thought of him when I watched yours.

[@GTGTO-su8bp]

On my 66 GTO the #7 is Purple for the Parking Lights --- Headlights on Parking Lights off. I moved the Purple #7 wire to the #3 terminal which is connected to the #4 terminal - Brown for the Taillights. Now the parking lights will stay on with the headlights. It's a safety thing for me as new 65 thru 67 Pontiac Tempest, Lemans, and GTOs before 1968 were headlights on taillights off, even tho the switch was setup for them to both to come on. That was made mandatory for all vehicles in 1968 for safety. It's possible it could work for Chevies built before 1968 too.

[@caylee3277]

i pull the tab put 2 positions and only highbeams come on. i dont get regular lights

[@joecl10]

One question I have is where do uou hook up the other end of the ground?

[@chriscraft77022]

ground only goes to 1 place on DC .. what’s my grounds explained video

[@28704joe]

Was the element you didn't know what it was a circuit breaker built into switch?

[@chriscraft77022]

thermal breaker.. yeah

[@28704joe]

@@chriscraft77022 Thanks! I was going to add one in the circuit , now I know it is not necessary. Never knew that.

[@Savade913]

So if I'm getting a negative reading is it bad?

[@luisgomez2062]

I have a 1967 c10 stepside and I'm having trouble with parking lights on front when I turn on headlights parking lights go off, any idea why?

[@chriscraft77022]

they are supposed to do that .. they are literally lights you left on when you parked the vehicle at night

[@sssur32]

Excellent. Thank you.

[@rickigunter1960]

That helped me.. thanks

[@georgelinder670]

Chris, I have a problem with the dimmer and parking lights. Can problems arise between the dimmer and turn signals on the dash portion only. If I signal a right turn without running lights everything is fine. I put the parking lights or headlights on and the dimmer switch full bright it signals on the dash only a turn in the opposite direction. Turn the dimmer down and normal indications return. Any thoughts?

[@chriscraft77022]

I would start by taking each 1157 signal bulb out.. and making sure it is clocked in the socket 100% the right way

[@marquesmoss5283]

I have a 86 c10(truck sat for 10 years got it from my grandpa) and the high beams won't work (brand new ones) the high beam indicator light was working but not anymore....the low beams work and so does all the other lights ....the switch does dim the lights in the dash.......so could my issue be as simple as taking out the switch and cleaning it ? (Old man said everything worked when he parked it)

[@chriscraft77022]

does that truck have the foot button in the floor to the left of the brake pedal or does it have it on the blinker switch? to turn on the high beams?

[@marquesmoss5283]

@@chriscraft77022 there's no foot switch and I'm not sure if the blinker switch controls the high beams. As faras i know i thought the light switch it self controled the high and low beams , because it clicks twice when pulled I'm learning as i go with the truck......

[@chriscraft77022]

@@marquesmoss5283 on the blinker switch you push it forward.. to engage the high beams.. check it out

[@marquesmoss5283]

@@chriscraft77022Thanks for the help.Turns out you have to pull the switch all the way out and the pull the turn signal lever back to engage the high beams. That saved alot of time trying to go threw and check all the wiring.

[@daltonnelsontrucking1259]

How does the knob come off? Is the a clip or do you just turn it a certain way

[@chriscraft77022]

there is a small button .. push handle all the way in... push the button and pull it out

[@Enamidone]

Hey bud I don't know if you still look back at this video or if I can get a response. But it's worth a shot, I have an 86 K-10 that the lights work the night before came out the next morning and I have no headlights do you have any suggestions or could you make a video for the full wiring walkthrough. I have power to switch but no power to the headlights and someone did a damn hid swap on the lights. So I'm about ready to just gut it and take everything back to stock, but I'm just kind of at a lost so if anyone has any suggestions

[@Enamidone]

Okay I know I just posted this but I also just figured out by process of elimination that I have a bad dimmer switch which wasn't creating a signal to the headlights. Problem solved

[@foreverwood1963]

Would that test not have worked with just with the 1 terminal to power ? Just asking why does it have to be jumped that way?

[@CinemaWhirli]

solid vid man. what's the tunes going in the background? Reminds me of american analog set.

[@zachhob]

Haha.. I was wondering the same thing. I assume you're referring to the jam from about the 4min mark to around 8min (before Sabbath kicks in).. I'm not sure, but I agree it's kinda American Analog Set-ish. Also, thanks Chris! I totally fixed my original switch & didn't have to replace it, thanks to your thorough video. You rock, man!

[@curtisballer688]

More 70-80 Chevy vids! :)

[@joekind1]

No dashboard lights and no door entry lights. Installed a new switch still the same problem. I'm thinking the new switch is also defective. I called the seller, said they would test the switch. Could there be a loose wire?

[@chriscraft77022]

usually not the switch.. check grounds... first..

[@joekind1]

@@chriscraft77022 Thanks, I replaced the courtesy relay and the center console printed circuit, got them working now.

[@joesalazar4675]

Do you think the reason my toe lights don’t work is because my switch is Bert, everything works during the day. But at night I don’t get no tail lights

[@chriscraft77022]

its usually never the switch.. but it could be,,, you have a TAIL LIGHT fuse .. and if thats good check the grounds for the tail light harness over by the tail lights.. you should have 1 for each light.. let me know what you find out..

[@joesalazar4675]

@@chriscraft77022 I will be in touch thank you for the fast reply

[@rhettburk4864]

I have an '84 k10 and the headlights/taillights cut out. I checked my fuses and they're all fine. Do you have an opinion or suggestion on the matter?

[@chriscraft77022]

+Rhett Burk clean up the grounds on the harness and check chassis ground from battery

[@mikerosenberger1631]

i have the 7 pin version and mine gets pretty hot. i wanted to install a relay for my headlights but am not sure which pin to connect to control the relay.

[@chriscraft77022]

if you are gonna run a relay the light switch doesn’t have anything to to with that.. find the wire that feeds headlights ( by headlights) that’s what you run to 86 to turn on the relay

[@mikerosenberger1631]

Thank you for your help

[@dwhollrah]

Good instructions... but what the heck were they doing to the poor guy in the back?

[@teabag402]

My headlight switch has no power on the large red wire. When I give 12 bolts via a jumper wire to the red wire my STARTER engages😮 what's the deal with that?

[@jeffmesser796]

Good info but your music was competing with your voice

[@jorgegrealty]

Im having problems with my 1990 g20 series van. I changed this switch because headlights would not turn on, but didn't make a difference.

[@mean_sbc8653]

This probably a little late but make sure your ground connections are good, if they're go ahead and test the wires, also make sure you have a good battery connection

[@GTGTO-su8bp]

Will all that crud inside the switch cause it to not work? My headlights won't come on, but I have lights everywhere else. I'm not an automotive electrician so I'm lost getting the headlight working again on my GTO. 😂

[@chriscraft77022]

Check grounds on headlights there is one for each

[@judgemelbye472]

how do I bypass the switch to turn on the headlights? Do I just put a jumper between #1 and #6?

[@chriscraft77022]

why not buy a new switch they are like $15 ...

[@omarsilva5056]

@@chriscraft77022 where at

[@nathanmarshall7523]

Why is there twelve volts coming from horn relay?

[@chriscraft77022]

depends on the car or truck I have no idea what you are working on

[@nathanmarshall7523]

@@chriscraft77022 89 jimmy, same switch, wondering why terminal 1 is "straight from horn relay" and 5 is from fuse box. Why two hots?

[@littlefield806]

Do u know if this switch would cause my brake like to stay on

[@chriscraft77022]

this switch has nothing to do with that

[@littlefield806]

Ok see when I flip the switch non the brake lights don't shut off or don't work if the switch is in but the brake switch is new and i checked the harness from the box to the rear harnesses and it's fine can't figure out why it's doing that and the harness for the tail lights is new it's on a 1978 Buick regal

[@chriscraft77022]

the brake lights are also the turn signals and hazards.. same filament side on the bulbs .. check the hazard lights first

[@bigrfish25]

'69 GP.. All lights work fine except courtesy when door is opened. Wire is there.. just not hooked up. Door pins wired and functioning. Anyone know which tab opens and closes this circuit?

[@pandabang]

I had the lights go out on my 84 K5 blazer, been working on it for about a month. Got headlights now but when the brights are on for too long they start blinking. Checked the fusible links, (mine were just threads) put in inline fuses, Put in a new headlight switch, and brights switch. The brights switch was burnt out. Old battery died while troubleshooting everything so I got a new one, wasn't charging either so put in a new alternator. Still have the blinking. I have consistent voltage going to red wire going to the switch, but when the lights are on, the yellow wire leaving the switch will blink the test light or show voltage drops on the volt meter. Could my problem still be cause by a bad ground somewhere else on the truck? Somewhere past the switch? I have grabbed all the wires in the engine bay and shaken them, can't reproduce the blinking that way. Could my brand new switch be defective?

[@chriscraft77022]

you need to take the headlight grounds off and clean them.. there should be one for each headlight

[@t-rodshader9593]

I know this is old, but I figured if share my experience. I rewire these squares a lot. There is about a 15amp breaker built in to the switch. It's so that if there is ever an intermittent short you won't just blow your fuse and lose them. But it sometimes with cars that actually turn on 4lights when on high will overamp the switch, I think there was a different breaker installed on some vehicles with 4headlamp switches at one time. But since gm uses small wires on some, they default the all switches to the 15amp instead of 20. I used a 91 core support+grille in my 85 K10 shortbed after my 350 was built. And the headlamps are usually wired to the winners for high. And the outters for low. I used a relay with the high to backfield the lows with the power from firewall with 14awg wire and a 25amp fuse so that the swiths actually don't carry all that load when in high. And only in lows. Which on 2 headlamp systems, it works like a tailight bulb. There is a 45w filament/and a 65w filament the ones with 4 are either top ones with two 45w filament. (One aims down; ones up) and the lower one's are 50w. The 89-91 grille has two like on 92+ where it's outer at 55w and inner at 65w.

[@briizcustoms9543]

@@t-rodshader9593 I’ve got a 1976 Chevy Itasca RV on a Chevy p20 chasis, the system is a 350tbi. After I got a new alternator put in my gages spin crazily, they ALL spin besides the battery gage one I’ve noticed. I’ve gotten it looked at by 2 mechanics and the wiring is fine according to them, they say it’s the cluster panel itself but I struggle to understand that as they were working perfectly fine before the new alternator. Also there’s a green wire, it was connected to something then I discovered it burned off at the end. I also noticed there’s two green wires coming from the headlight switch if that matters at all, dark green and light green. At this point I’m wanting to check it all out myself, do you have any advice?

[@t-rodshader9593]

@@briizcustoms9543 is the wire you seen burned outside under the hood?.. it could very well be a link to something interior related, but I have a feeling you may have lost a ground somewhere and found path through a wire too small and burned it, either that or since you did just replace the alternator, and I've seen this more times than not, it overcharges at some point, and if your not paying attention at that very moment for however long it can put out 19volts and you'd never know without the lights on or it being high enough to burn out the ignition coil so alot of times fuse links will end up burn led and cause weird things to happen or loose power to certain things from the battery or to the dash inside.. I'll have to look at the diagram for the chassis and see what I can find.. that is interesting and sounds a lot like a ground issue🤔

[@briizcustoms9543]

@@t-rodshader9593 Let me know what you find, the mechanic claims he fixed it so I’m just waiting to get the RV back to see

[@JuanGomez-ih3zn]

I gave to Remplace fuse box on my 1970 Monte carlo

[@jeremyjames83]

What if you have no power on either hot wire to the switch?

[@joerogerio]

I have a 73 Buick Electra and the panel/interior lights would not function. So I replaced a burned out headlight switch and headlight switch connector but......the replacement connector is different and has different color wire colors. What do i do now???

[@chriscraft77022]

are you saying like they dont sell an exact repro of yours?

[@joerogerio]

+Chris Craft Yes

[@doja954]

Joe Rogerio I have a 73 electra all lights work but headlights. You fixed your problem, lmk

[@cadiman12]

I have a problem with my 65 Pontiac Catalina 4 Dr on the switch, parking lights & dash light up as well as the taillights, but when I go to put the headlights on, low beam & high beam doesn't go on... I changed the switch, same problem... Could there be a break in the wire somewhere or could it be the headlight relay? Any help would be appreciated... Thanks... Forgot to mention, my 65 Pontiac has the 8 pin on the switch...

[@chriscraft77022]

first thing, locate the 2 grounds on the core support (off the wiring harness) and clean them up... second, check the chassis ground to the front fender from battery negative terminal... BASICALLY.. check the grounds to start with.. there is no headlight relay (unless that car has one and i dont know about it) im pretty sure thats the horn relay you are talking about

[@cadiman12]

Chris Craft your right, that's the horn relay I was talking about on the driver side inside fender... Why did I say headlight relay?! I don't know what's the matter with me.. ;) that was MY mistake... I'll check into that what u suggested to my reply... Thanks... I'll get back to u... Right now my car is at the shop getting brakes done... JEFF

[@chriscraft77022]

just clean up the grounds.. get an assembly manual if you can to see where they all are... thats where i would start and hopefully where the problem is

[@alimehsen9310]

Possibility Check the Hi and Low beam switch on the floor

[@michaelkhalilah1460]

When I in plug in the ground it blows the fuse

[@DavidDonoho-p5t]

I could use some advice. I have a 1967 cutlass 442 with no dash lights everything else works fine. Ive tracked it down to the fuse box no power on the incoming side of the 9amp fuse.

[@efrainlara3561]

My tail lights dont work at all. No Reverse or brake. What do I look for

[@chriscraft77022]

the ground on the tail light harness first clean it

[@efrainlara3561]

@@chriscraft77022 okay I will.

[@BigRichEHhthang100]

Can I get the diagram?

[@caylee3277]

how do you turn on highbeams in 85 riviera

[@chriscraft77022]

you have a high beam switch... probably on your steering column with the wiper switch... not 100% sure because I have never messed with Buick’s