Hey guys I was searching around for any help on wiring, an aftermarket, fuel cell level unit to the factory fuel gauge. We are building a custom set up with a 10 gallon fuel cell and a quick fuel fuel 105 pump, and we wanted to wire the fuel level unit to the factory gauge. I searched around and was able to find an electrical component location diagram, as well as a full wiring diagram breakdown for the gauge cluster and it lists the wires as

white /green stripe as the gauge level
white / red stripe as warning light
black/ red dot as ground
Blue red dot as power for fuel pump (not being used)

after I wired it up, the gauge climbed to full and stays there until I unplug the level unit when I probed the wires at the harness in the rear. The white wire with green stripe has a pulsing voltage reading blue with red dot is confirmed as steady 12 V power has anyone attempted to do something like this

 

its resistance based. did you use and aftermarket sending unit? the oem will read a certain resistance at full and your new one likely has a different range.

 

The fuel cell and sending unit it came with are aftermarket. There was no parameters or prints supplied just the normal ground screw lug and positive lug on top. If you know what the resistance specs are that would be great I’m assuming there can be a resistor put in line to correct that?

 

 

that help?

 

If you have the old one and the new one just measure the resistance at a certain spot and then add a resistor wherever you want, it’s probably best to check them at several locations in case they sweep over different ranges.

 

We unfortunately don’t have the factory one as it was thrown away with the factory tank last year. My son and I had put the build on stand by when my dad passed away earlier this year. Reading the tank unit is straight forward. Would I read the gauge from the back of the cluster or at the harness. We really appreciate all the help this has been a huge task to get this beast running.

 

if you go off the numbers i posted the difference between the front and rear is likely just the wire run. if youre in the ballpark you should be good so just do it at the top of the tank to save the hassle.

i also saw this on ebay, looks like you just run it in line to correct the mismatch.

https://www.ebay.com/itm/38495221676....c101110.m2109

 

I was at the shop earlier and took some readings on my meter and got 2 ohms at E and 84 ohms at full on the fuel level unit. I put it back in the fuel height and was 34 ohms at fuel height, so roughly under a half a tank. I tried to check the numbers at the gauge and I was not getting a correct reading. the reading at the gauge I was getting was 26 ohms with the car off. When I turn the key on the needle slowly crept up to above half and stopped but the reading was flickering and wild. when I shut the car off it’s slowly crept down and read 26 ohms the whole time. I also went to the harness in the hatch where I tapped into and the voltage reading from the white/green gauge wire was also flickering and wild and wouldn’t register any voltage reading.I haven’t figured out how to wire in the low level fuel light but Would this have anything to do with not wiring in the low fuel indicator light wire white/red?