I have a 1996 Jeep Cherokee 4 wheel drive 4.0 L 6-Cylinder (no idea what base model) and I recently replaced the fuel pump due to it dying on me one day. After installation I noticed the pump wasn’t priming and the car wouldn’t start. I first thought that it wasn’t getting power but the fuel send unit was working because my fuel gage worked (all in the same wiring harness). I then proceeded to do some research and came across threads saying to check relays and fuses and all work fine. I then checked voltage from the wiring harness that goes to the pump and got the 5.8 constant volts and 12 when turning the key. I checked the pump itself by jumping it off the battery and it works fine. I started checking continuity of the wires that are in the fuel tank specifically the main power wire to the pump and found that it was not making a circuit. I then replaced it with one that came with the new pump. Still nothing. I literally don’t know what else to check. If anyone could help me it would be greatly appreciated. Thanks.

 

Problem: Fuel pump isn’t turning on and it’s a brand new pump.
What I’ve tested already:
Fuel pump itself (works)
Relays that could possibly interfere (all work)
constant voltage from the wiring harness before the pump wiring (constant 5.8)
voltage when cranking/key turn (12)
Continuity of the power wire to the pump inside the tank (wasn’t passing current so I replaced and still nothing)
I also know power is going through the harness because fuel gage works. I have no idea what else it could be. Please help.

 

Have you checked all your grounds? Also, it shouldn't have one being a '96, but do you have a fuel pump ballast resistor in that one? Looks like this:

 

I'm almost certain I don't have one, but I will check. The only ground (I think its a ground) I have checked at the moment was the wire that attaches to the metal plate that the pump assembly is attached to. Where else should I check?

 

Thought sure I already answered you... weird. Anyway, refresh ALL the grounds under the hood. There's one that goes from the battery to the firewall, one to the starter, one to the alternator, and one to the engine block. There's also one that goes from the head to the firewall, but that's just a ground strap to eliminate radio noise.

Pull off all the grounds, get a wire brush or sandpaper and clean both surfaces to shiney metal. Apply dielectric grease to the lug and reattach the terminal. You want to snug 'em down real good, but don't overtorque them or you could strip the lug.

Also, in case it wasn't clear, if you have the ballast resistor it will be under the hood on the driver's side fenderwall usually next to the brake booster or the air filter box.