fuel sending unit wires

[bigkat79]

hey folks, got a quick and easy question. i dropped my tank because my guage reads about 3/4 past full the whole time my truck is on. when the power is off the guage reads full or a little less. what im looking for is pictures of where the pink power wire runs to from the tank. i have what i assume is the ground coming from the sending unit (also not hooked up to anything) but i think i see where that is supposed to go, but the pink power wire is nowhere to be found under there. i looked at the wire bundle to the fuse box and see a pink wire in there but i have no idea where it goes into the cab so i can trace it back towards the tank.

thanks in advance for any help.

[DnStClr]

I'm assuming your truck is a 79.The pink wire is the signal wire. It runs from the sending unit at the tank directly to the back of the instrument panel electrical connector. According to Capt. Kaos wiring diagrams found here on this site, the pin is #30. The wiring schematics are found  here- (hope it helps ).
http://forum.73-87chevytrucks.com/smforum/index.php?topic=11766.0
Forgot to add- I think the wire physically runs up the left (Drivers) side of the chassis in a bundle.

[frogman68]

Actually the wire goes to wires 7 and 18 (18 if dual tank)
Check the ground (even if it looks good take it off and wire brush it and the frame with some new washers)

[DnStClr]

Ditto on the ground wire. They sure cause a lot of faults. I'll recheck myself with the schematic on the pink wire.

[frogman68]

Ditto on the ground wire. They sure cause a lot of faults. I'll recheck myself with the schematic on the pink wire.

I just installed the gages in a 84 and found this wire was busted I just ran a new one and a new ground..

[DnStClr]

Frogman. did ya have any problems with the tail light?

[frogman68]

Frogman. did ya have any problems with the tail light?

Hehe

At that time there was no wiring harness or tail lights but now that the wiring is done they work fine

[bigkat79]

hey all, thanks for the information. i got under the truck and found the bundle of wires BUT there are only 4 wires in the bundle and the diagram shows there are supposed to be 5. anyone want to guess which wire is missing? the pink fuel sender wire! i followed the wires back up under the hood to the junction box (?) by the brake master cylander and there is only 4 wires in the bundle all the way. so i have no fuel sender wire what so ever outside of the cab. i did pull the dash and found where it is supposed to be on the instrument panel wiring and it IS there.

oh and since i forgot to mention it so far, it's a '78 single tank setup

[bigkat79]

here are some pictures to reference what im talking about...

the 4 wires that are in the bundle that runs down my frame rail


the "junction box" i was talking about. does anyone know where the pink wire should go in there? and how i would put a new one in?

[123 pugsy]

Check the wires coming thru the tube close to the starter motor.
That's where mine runs back. On the passenger side.

[DnStClr]

Keeping in  mind that my truck is an 87, mine (there are 2, a pink and a tan) go back thru the wiring tube on the drivers side. The pink wire goes to the connector in your last photo. It goes thru the 3rd space down on the r/h side of the connector, below the yellow wire. It sounds like the wiring was definitely different on the earlier model trucks since Pugsy's wire goes down the opposite side of the frame.