Hi All
I am bringing a 94 3500HD back to life...
Have zero history on the truck,it was unwanted and i had space in my yard.Had a rebuilt engine installed and a decent dump box so i saw value.
Got it running by supplying the lift pump with it's own power source.Starts and runs good while the battery is hooked to the lift pump.
In checking the wiring to the lift pump,i got power at the pump but no ground.
It has the old relay on the firewall for the lift pump which i tried a couple others.I tried to find the ground in the relay wires that went to the pump with no luck.
Then it was the end of the day.
Does anyone know where the ground for the pump comes from? my guess is the OPS fits in somewhere.
I did not check for ground as it was running.
Thanks Thomas