How to Calibrate and Fix a Fuel Sending Unit

[@ellesmerewildwood4858]

Back in the day, working at Flexdrive Instruments, the Aussie arm of Stewart Warner, the tank senders were always set slightly low at full. For instance the 73-10 ohm tank the 10 ohms would be set at 9 ohms so the gauge pointer would read slightly above full. Apparently, back in the day, people liked their fuel gauge to read slightly above full. Gauges were always calibrated exactly on the mark. Low on the sender would be set at correct ohms or a little higher like 75 ohms would be acceptable. These days, when ever I repair a tank sender I always set them the same way as it was done at the factory, always a little higher at the full mark (9 ohms) but never higher than the 10 ohms. Anyway, just 2 cents worth from the old school instrument guy. 🙂

[@Kane-O-Mansfield]

Thank for the video. Helped me fix my motorbike fuel sender 🙌🏼

[@williamgrissom9022]

Interesting, but the "fix" by setting stops on the float motion effectively makes it non-responsive around the F and E limits. At least keeps the customer happy since they see exactly full on the dash gage. More critical is how accurate it reads near empty. Perhaps the stop is why most people figure they can keep driving a bit more when it shows "E" on the gage and the needle stops moving.

[@chinakmeru]

I Completely agree. This method is only putting limits to the float travel it is just cheating the gauge.

[@oxideblitz7283]

Wish there was a video for the majority of other fuel sender units

[@markfeuerherdt2338]

What aftermarket fuel gauge do you recommend to use with the Crown sending unit? I want to use it on my 1980 CJ5. Want to keep the speedo cluster in the dash. Thanks.

[@paulgeorge9614]

My car uses a different style unit that won’t allow me to bend tabs to adjust the reading my manual calls for 3ohms full/80ohms empty the replacement unit I received reads 6.5omhs full/82.5 empty will that cause an issue ?

[@NoName-tm2yq]

Where do I go to get an OEM sending unit spec for a 1986 Toyota with a 22R engine?

[@coreysmith2753]

My c4 fuel sending unit electrical wires are not working, not getting any power through the wires. Bought aftermarket sending unit but the electrical connectors aren’t the same size as original one. Any ideas need help!! Please, thanks in advance

[@jasonkent2390]

HI IS THIS FOR ANY TANKS ? I HAVE A RV AND NEED TO DO THIS.

[@etechjd8260]

thanks>Not sure what is MD but good info

[@GilbertR-xo9rm]

How to calibrate Dodge Magnum 2005 3.56 cylinder Rear Wheel drive SXT

[@markfeuerherdt2338]

What ohms setting on your multimeter do you use? I want to calibrate my Crown sending unit for my 80 CJ5. Tank is a 15 gallon poly tank from MTS. Thanks.

[@wojaktothemoon3324]

great sir. thanks!

[@Mr420Rizla]

great help as i'm about to do my 1970 ford zodiac thanks

[@londriver4643]

You can get those digital gauges that can be calibrated at the back with a simple screwdriver

[@markfeuerherdt2338]

What kind?

[@arkman8109]

Thank you

[@Giorobot]

Very helpful new sub here

[@williambasore810]

I rebuild senders professionally and this is not how you calibrate a sender. The two stops are intended to keep the float arm from hitting and drumming on the top of bottom of the tank. The actual calibration is done inside the resistor housing by adjusting the location of the sweep arm. As Ellesmere Wildwood pointed out the resistance at full should be no higher than 10 ohms. Setting it a little lower compensates for the series resistance in the rest of the circuit. As a percentage being 1 ohm off at 10 ohms is meaningful. At 73 ohms empty one ohm makes exactly no meaning full difference. Because of the design these senders are only calibrated at the full position. If the empty reading is too high it means that you are compensating for series in the connections in the sender by having to really drop the full setting to get total resistance in the sender down to 10 ohms.

[@JT-yl7my]

Where are you located? I’ll let you fix & calibrate my sending unit

[@jjpaul75]

Hi William…So, with a full tank, my gauge says I am a hair above half tank. When I am empty, my gauge says I am around a quarter tank. How do I get full to be F and empty to be E?

[@jjpaul75]

Also, at 45mph, my gauge says I am going 65ish. It’s a new cluster and new wiring harness put in by a Jeep shop and this is what I get. Thoughts?

[@williambasore810]

@@jjpaul75 What vehicle are you working with?

[@williambasore810]

@@jjpaul75 The speedometer is typically driven by a mechanical cable. The number of teeth on the end of the cable determines the ratio. If yours is like that then you need a gear with more teeth. Or it could be an electronic speedometer and that is entirely different. What vehicle?

[@jeffs5913]

I wouldn't put the filter on at all. Because you have a filter after the tank anyway and it's a pain to get to.

[@DirtyDangleDaryl]

The purpose of changing the filter in the tank prevents any impurities from going through all your lines before your in line fuel filter .. you're going to have a higher chance at general wear throughout everything before the in-line filter

[@bobreese4807]

So..2 years ago, I asked a mechanic to replace my 1998 Dodge Caravan 2.4L fuel filter that was changed 22 years ago. When he did it he cracked the fuel pump connectors and it leaked gas. I paid for the part and he did labor free. Bosch. The gauge read low. Still had 5 gallons left when gauge was at E. He replaced it and same level issue. I said forget it and was same for 2 years and 2 months. The sensor started making the fuel gauge needle go down and the chime came on with the gas tank idiot light coming on. I GOOGLED it and saw complaints like this and saw might be caused by sulfur in gas tarnishing the metal on the sensor metal.. I put in 2 bottles of Techron plus and for a time chime was lot less but now is awful!. So far I can't find what metal the sensor windings are made of for BOSCH. I see 2 brands, one using gold (Delphi) and other silver palladium. THEN... I see ranges of 70 to 1050 OHMS for replacement pumps (ON Rock Auto info on their pump assortments. and then I see 33 to 240 for Bosch and American makes. I was about to put a cheat resistor in the harness to make it so I could stop the low level CHIME stop. BUT now I don't know what value to put in. I was going to put in a 680 or 750 OHM but when I saw this new range. I put a temp hold on this cheat. The gauge anti- slosh makes the needle move slower but the chime comes on right away. I think the float needle is getting to a dead high OHM spot on the sensor. I found out a couple weeks ago that Bosch went to a lifetime warranty.. but there are qualifiers and so I will see what push back I get from Bosch.