Sending unit wiring.....

[vwfastg60]

Ok so Im going back and fixing the pump tank issues i had and i have run in to an issue.

3 wires coming from the sending unit, Yellow black and red in the tank. The wire that is yellow and runs to the little senor thats not part of the sending unit doesnt have a wire out of the tank. The harness running to the pump and sending unit i a 4 wire and the tank plug is 5. The guy that helped me before spliced that to the signal wire for the sending unit. My gauge used to jut fall under 3/4 tank. Could have been the 87 sending unit but i want to be sure this time the gauge will work. Does anyone know what that thing is and What it wire to? I chased the wiring all the way back to the plug in the truck and the wire count is the same.

Thanks for any help. Sorry if this is a mess but my laptop in the garage has a few keys that are now messed up. lol

[vwfastg60]

Ok so after giving this some thought I have come up with a guess. Please correct me if I'm wrong.

The sending unit should only use 2 wires. Both sending units are from rigs with a low fuel light. Now with out talking to Nate to find out if the white cab had one I assume it didn't. Soooooooooo what I'm getting at it is red and black are the wires for the sending unit and the yellow wire wrapping around the little sensor is for the fuel light. Giving me an explanation for the missing wire in the truck harness. I will also note that part of the wiring was never changed in the cab and it doesn't exsist there either. That would make life easy so I'm guessing I'm wrong.

[mrdoug]

from our conversation yesterday, sounds like you were on the right track. That sensor (with the orange rubber baffle thingy) is the low fuel light, so it doesn't need to be connected.

Did you get it all back together and running?

[vwfastg60]

yeah i did, It works perfect. Put a half tank in and drove it and it works and then filled it and it woks perfect. Seems to be placed right in the tank as it should...I measured it 20 times. Tried to over fill it a bit and see if i got any leaks from the welds and havent found a thing! Im so excited to have that working im going to order hydro assist and new lights for it this week. Need to get the name of those rock lights you have again so i can get some of those guys ordered too.