A Couple of Issues...

[Raleigh]

So while looking for a reason that my stereo stopped working I found this relay unplugged.

It is on the firewall behind the fuse/battery block cover and I have no idea what it is for.


Another thing is when I use my signals, brakes, windows or just about anything my voltage drops big time.
I know one of my batteries is weak, so I am going to start by replacing that.
The engine never fails to start, luckily no issue there.

 

[ak diesel driver]

fuel pump relay. if it was unplugged maybe someone bypassed it

 

[Raleigh]

So it is the lift pump relay? Interesting, there are 2 power leads that have been added, I know one is for the brake controller, the other may be for the lift pump.
I will have to look into that.

 

[buddy]

That relay only powers the lift pump when you are cranking, so it will run without it. Typically the oil pressure would come up while cranking anyway after a couple seconds and power the lift pump through the OPS if its working.

And then someone may have bypassed both and powered the LP from the ignition, do you get the LP running with just the ignition on?

Batteries should be replaced in pairs or the weaker one will continuously kill the newer ones from a difference in potential and resistance

 

[Raleigh]

I have never actually heard the lift pump run at all, it doesn't run when the ignition is just on.
Hell I was looking and didn't see it on the frame rail, is it in the tank on the sending unit?

 

[ak diesel driver]

it will only run while cranking on 94-95 and after the oil pressure has come up. it's located on the frame rail under the drivers seat