97 Jeep Wrangler 4.0 Fuel Pump


#1

My 97 Jeep Wrangler is not recieving power to the pump, I’ve checked fuses & cleaned ground wires, I don’t know what it could be.


#2

I would guess it has a relay. The relay may be out. Check a wiring diagram if you can find one.


#3

How do you know that it doesn’t have power?


#4

The relay is in the fuse panel on the passenger side under the hood. You should be able to use a jumper wire across the two terminals in the fuse block to substitute for the closed relay. Another tactic is to substitute another relay, like the one for the A/C clutch, for the fuel pump relay. If any two have the same number, they are the same. The A/C is the same.


#5

I checked it with a circuit tester while my Son cranked the car.


#6

You must remember that, if you are checking for power at the pump with a multimeter, there WON’T be any because there is power ONLY for the first two seconds of key-on, or, during engine cranking (or, running). If you think that the problem is a lack of fuel, remove a small tube from the black plastic intake tube and spray a two second burst of Starting Fluid spray (available at your auto parts store) into the tube. Then, try to start the engine. If the engine runs for a couple of seconds, the problem IS fuel related. Go to www.carterfueldelivery.com/fuelpump for a good, informative acticle on your type of problem.


#7

There should be 4 wires going to the fuel pump. The dark blue/lt green and brown/yellow are for the fuel level sender. The black wire is the fuel pump ground, and the Dk. green/white wire is the fuel pump power. If there is no power on the Dk green/white wire while cranking then there is a brake in the wire between the fuel pump relay and the fuel pump, the fuel pump relay is bad, or the ASD(auto shutdown relay) is not providing power to the fuel pump relay.

Remember that when the key is turned to on the fuel pump relay is only powered for 2 seconds to prime the system then it is turned off. When the ECM is signaled that the engine is cranking it again applys power to the fuel pump relay. Double check for the initial 2 sec power at key on and power while cranking. If no luck I would recommend swapping the horn relay for the fuel pump relay and try again.
~Michael


#8

Also double check fuse number 16 in the under hood fuse pannel and fuse #11 in the inside fuse pannel.
~Michael