Lift Pump

[katrinekid]

I have no power going to my lift pump, replaced the pump solenoid and still nothing. Is there a fusable link in the circuit or something else that I,m missing. Any help would be greatly appreciated.

[john8662]

Check the Oil Pressure Switch, it's located on the back of the engine (driver's side), it just looks like your oil pressure sending unit (because it is this as well).

This supplies power to the lift pump.

You also need the socket for this component to remove and install.

J

[westport70]

Check fuse on firewall .Learned hardway yesterday.

[katrinekid]

Thanksfor your replys. I thought the oil pressure switch only took over once the engine was running, shouldn't i have power to the pump when the key is on? I checked the fuse and it is good.

[JohnC]

shouldn't i have power to the pump when the key is on?

On MY94 trucks the pump runs only if the starter is engaged or the engine has oil pressure.

[DickWells]

I'm afraid this might not help you, but (just maybe) it might, also:(.
I used to keep a piece of small, stiff wire, bent into a U shape, under the power dist. center cover under the hood for jumping the lift pump relay. Trouble is, I can't remember the two sockets to jump! However, I did prove, by mistake, that I didn't blow anything up by jumping the wrong two. I THINK that the sockets were 85 and 86. You have to pull out the relay, and the numbers are on the bottom. Jumping the right two will run your lift pump, regardless of the condition of the OP switch. If something isn't open between the dist center and LP, you'll hear it running.
If you search the archives in TDP, you'll find data on how to put a relay into your OP/LP circuit to take the load off your OP switch. I did this on my own to the 95 Burb, back before the data became available, and never had to buy another OP switch. The contacts burn out without a relay in there, and a new switch is costly. A relay was less than $10, IIRC.
Ah, heck, I broke down and called him anyway. The sockets are 85 and 86. He took the wire and jumpered them and the LP ran up to pressure and shut off? Huh? Oh well. Eighty-five and 86 are the bottom left and upper right as you look down at the dist center with the relay removed. I think, but not sure, that the factory relay has a timer to pump up fuel before the engine starts. I never did prove that the factory relay was bad in my unit. It's still there, and it's been at least 8 years since I had anything go wrong in the LP circuit.
Good luck.:)
Dick Wells