Fuel gauge issue 1977 c10

[ikiahslb7dmax]

Ok so my neighbor has a 1977 c10 chevy with a 1984 corvette engine and im helping him figure out his wiring for his fuel tank . It worked before he let the truck sit then I came around helped him get it running again I had to rewire the electric fuel pump to work it wasn't getting power . Now im trying to figure out what wire comes from the cluster to the fuel pump to get the gauge working again ik it works because I used a multi meter to test it. It reads 33 omhs which is about right what should I do should I cut the pink wire coming from the cluster and attach it too my purple wire coming from my pump

 

[Smtty58]

Did he wire in the fuel pump relay? Don't know if he used the Corvette harness, if so there is a single lead sticking out of the harness near the relay. Put 12 volts to this and the pump should come on.

 

[NLD79K10]

Purple is the right wire for the level signal for the sender unit for an '84 Corvette, connecting it to the pink wire going to the fuel gauge should get you sorted.

 

[75gmck25]

The wire from the cluster is for the fuel gauge, but AFAIK it would not work to power a pump or relay. It does have 12 volts with the ignition on. I think it’s more common to use something like the wiper power to feed a fuel relay, since it is ignition-switched.

On newer FI trucks they use a 3 terminal oil pressure sending unit to control power to the fuel pump relay. The fuel pump is only powered by the relay if the engine is running and has oil pressure.