Fuel pump relay location

Hello,

The relay is located under the hood here is a guide to help you test it and the location in the diagrams below.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check and test the fuse no.22 15 amp and fuel pump relay.

I recently removed my engine for repair it now installed and begining to try it but my fuel pump relay is clicking constantly what suggestions do yuo have for me too check

the clicking of the relay, would mean a good relay, I think your problem is the fuel pump

Was driving it and it quit running. Had it towed. Key on sends 12V to the fuel pump for just a brief second, but does not energize fuel pump. Of course, I replaced pump and filter. Still no fuel pump engagement. The fuel pump will run if I put 12 V to it, but I am not able to get it to prime and send fuel to the rail, tank is about 1/4 full. Back to the real problem. I do not have 12V to the fuel pump except for a few milliseconds. I have checked ALL the fuses (3 times, because sometimes I am stupid), I have replaced the fuel pump relay. The fuel pump relay has always made an audible click indicating mechanical function. I pulled the PCM,ECM or whet ever it is defined as on this particular vehicle. There was some pretty visible corrosion on, maybe 2 or 3 pins, cleaned this up w/dental picks, elect parts cleaner and compressed air. Still no fuel pump. I would literally have to tear this car apart to trace the wire from the fuel pump to the power center. I have a Haynes manual which is for all intents and purposes useless in this instance. If I had a good wiring diagram or just the info to pin it out I might be able to figure it out. I found a Jeep 1993-94 2.5 and 4.0L EFI powertrain Diagnostics factory service manual. Would this manual provide the info. I need to further diagnose this vehicle? Any help would be greatly appreciated. Thanks, John V.

Try swapping the ASD (auto shutdown relay) with another one (a/c) and see if that will work. If the PCM doesnt power up, the rest of the system wont work properly

Just to keep everybody posted. The brand new Airtex fuel pump assembly was bad and that's why I couldn't get it to pump/prime. Installed a new pump assy, but of course still no power to the pump, except for just a brief second when the ignition key is first turned on. Vehicle runs perfectly when I hot wire the fuel pump. Anyone have any suggestions? John V.

Oh, replacing both the ASD and fuel pump relays was the very first thing that had I tried. John V.

John, I need to know exactly which Cherokkee you have. There are 7 different versions

Replaced fuel pump, drove jeep a few times in town. Now jeep will not start. Fuel pump relay is working fine but pump is not kicking on??

I finally resolved the fuel pump problem on this Jeep Cherokee. It is a 1993 Cherokee Sport 2 door. It has a 4.0 litre 6cyl., auto, air , 4wd. I purchased the factory service manual, I traced the fuel pump circuit and discovered that I was losing power at the "fuel pump ballast resistor" It is my understanding that this is put in the circuit to reduce fuel pump voltage and thereby noise, under normal driving conditions but is bypassed by the ECM and a "bypass relay" under WOT conditions. The service manual did not give a spec for this resistor but it ohmed out at 78ohms. Seemed kind of high to me. Tried to find the part, but nobody (not even the dealer)knew what I was talking about. I bypassed it, everything worked great. Finally found the part and, new, it had exactly 1.1ohms of resistance. Replaced the bad resistor now everything is peachy. John V.

did you flush the tank when you replaced the pump????

Roy

John,

I too have the 1993 Jeep Cherokee Sport, 4dr, 4.0L and 6cy. Our problem is very similar I repalced the fuel pump and the fuel filter. Just can't get the fuel going into the line, the fuel is running and measured at the connector to the fuel pump, I am getting only 6.832 VDC. Tried the bypass on the resistor, still won't work and the ballast resistor measured at 1.5 ohms.

With all the experiences that you had on this problem, may be you can shine some light to this ...

Dennis

No i did not.

Well Dennis, you need to figure out where you have 12v. in the fuel pump circuit, then where you're losing it. 12v. should be going to the fuel pump for 1 sec. when the ignition is turned on or constantly when the starter is turning the engine over or when the engine is running. I would confirm that the fuel pump is working by VERY CAREFULLY jumping 12v. directly to the fuel pump to see if it pumps fuel and runs (make sure that you have correct polarity). If that works get a 12v.(dc) buzzer or light then see if or when you actually get 12v back to the fuel pump. If you don't want to trace the circuit and just punt, I would clean every ground and plug connector in the F.P. circuit, I would check and clean the big ECM connector, I would replace the fuel pump relay and I would eliminate the ballast resistor . If you truly have a 1993 I could probably help you out w/a factory wiring diagram (if your patient). Good Luck. JohnV

this may be the reason for the first failure as well as the current failure. dirt can lock up a pump new or not in a matter of hours.

consider the tank is over 20 years old and needs to be flushed

Roy

I have been working on my 93 Cherokee because it has the exact same problem. I've done the same things you have so far. Where is this ballast resistor? It sounds like that is the problem in my vehicle too. Where did you find this part? or did you just find a 1.1ohm resistor and replace the piece? Currently i just have the fuel pump hot wired with an in-line fuse holder and I'd really like to get this solved.

Makes sense. Iam sure dirt particles could get thru the strainer. Thank you

Jeep starts fine sometimes, runs, restarts.
Sometimes will start, but not stay running. Found little to no fuel in injector bar valve when this happens. When it runs, plenty of fuel present.

If I need to replace fuel pump or relay, where is the fuel pump physically located on the gas tank?

Do I need to drop the tank? I just filled it up before this problem started so it's going to be heavy with fuel.

Is there any tests I can do to find out if fuel pump is the cuprit?

Help!!!

[email protected]

The ballast resistor is located on the drivers side fender. It is a piece of white ceramic material mounted to the fender with a sheet metal screw,has 2 spade terminals, is essentially rectangular. I don't really believe it is needed in the circuit for the fuel pump to operate properly. You can just jump it out and leave it like that. The resitor reduces the voltage to the fuel pump under NOC to extend fuel pump life and reduce fuel pump noise. Any knowledgable Jeep dealer should be able to provide this part. John V.

If the pump is running but creating low pressure it is probably the pump. Yes it is located in the fuel tank . You will need to siphon the gas out.You will need to verify fuel pressure or lack of at theengien with a gauge (see video). If you do replace the pump, it is a good idea to change the filter and relay

https://www.2carpros.com/dia/test_fuel_pressure.htm

good luck

Roy

I had the same problem. It was hard to find as the resistor worked fine while cold, but freaked out when hot causing the fuel pump to shut down. It was hard to find due to the temperature breakdown. Bypassed the resistor and it runs fine.

Thank you so much John for this even 5 years later it helped me, I tried hot wiring with fuses and a external relay and I still couldn't get it right, I found this article pulled out that mess of wire, connected original connections to fuel pump. I then removed that ballast resistor and connected those 2 wires. Turned over and continued running. After months of replacing part after part you helped me with a single paragraph and I thank you.

I have a 1998 Jeep Grand Cherokee Limited with a 360, 5.9 litre. I just recently replaced the starter. A week later, to the day, I break down at the store. It cranks and is getting spark and power. So I had it towed to my garage, I automatically assume it's the fuel pump. I do a few trial by eliminations...1. I checked to see if I was getting power to the fuel pump with the key on, but nothing...2. I checked the fuel pressure, but there's hardly znything there just a faint smell...3. I check ALL relays and fuses, but they seem fine... 4. I hook a PCM to the jeep and get the error code 1282( Fuel Pump Relay Control Circuit )...SO NOW I don't know where and what to DO. I'm thinking it's the ECM and was wondering if I can find and repair the relay in the computer? Or do I just need a whole new ECM? I was Hoping I could get some GOOD news and there might be something else I can try? I would HIGHLY appreciate ANY and/or EVERY advise on what to do next, b/c I'm in dier straits!!! Please Send Help?!?!?!

What relays have you checked and how did you check?if it has an ASD relay pull it out and reset it back in and see what happens. The computer energizes the ASD relay-and in turn might power the coil/injector/s and fuel pump something like Chrysler products Could very well be the PCM

Good to hear, please use 2CarPros anytime we are here to help.

Cheers, Ken

For some reason, we don't always hear the fuel pump kick in when the ignition is engaged on our 93 jeep grand cherokee laredo. When it's cold and we don't hear the fuel pump, it won't start until we mess with turning the key off and on until we hear the fuel pump. I've changed numberous things trying to fix this problem and it's hard to really know if the problem is solved because we have to wait until in the morning and see how it starts. So far I've changed the following: Fuel pump, Fuel pump relay, ASD, Fuel pressure regulator, Fuel filter, Ignition switch and I think that's it. Not sure what to change next so I need some help! It used to start perfectly and I suspected the fuel pump, which I changed first. Now I've changed everything I can think of. Any advice? Thanks!!

Do you have ignition spark and injector/s pulsing??

Yes, there is no problems with the ignition spark or injectors pulsing. The only time the problem is present is when the jeep is cold or has sat for a few hours at a time. It runs perfect after starting. The fuel pump has started sounding "different" today though. I have a feeling that the new fuel pump I put on is actually bad too. I always hear the relays clicking and everything when I turn the key to engage the fuel pump but I dont always hear the fuel pump kick in and it won't start when I don't hear it unless I've just shut it off and the lines are still primed. The problem seems to be getting worse. Another bad fuel pump maybe? Is that common? Thanks!!

i got a 1997 jeep cherokee, i get no power to fuel pump at all, i checked the relay and it works, but when i test at fuel pump i get no power, there is power going to fuel pump relay, but no power comeing out of it, can you help me?

There would be two voltage circuits at the fuel pump relay. One for the circuit/load side of relay, one for the coil/control side of relay. Both circuits are fuse protected. Voltage for the control side of relay, goes hot with key on. Voltage to circuit side of relay, is hot all the time. But, unless the relay is energized, that voltage on the circuit side doesn't go anywhere. When the relay is energized, that line with the arrowhead on it, moves to the other terminal.

Engine cranking, do you have any spark at the plugs. If the computer doesn't see the proper cam and crank signal during cranking, you may not have fuel pump action or spark at the plugs or injector pulse. Any applicable trouble codes?

My jeep would backfire and almost stall, but I could turn the ignition switch off, then on quickly, and it would stop backfiring and run a little better for a mile or so, then the same thing again. Now the fuel pump will not work while in the tank. If I take it out and run a jumper from the battery, the pump motor will run. I am only getting 5.6v to the pump wiring harness plug when I turn on the ignition. I can't even find the pump relay. The Haynes manual says the system has two ballast resistors, but the auto parts stores say they don't show one. Frustrated! Got any ides? Thanks so much for reading this.

At the pump connector, were you testing the proper wire for voltage, dark green wire with red tracer. A no load test on a fuel pump isn't worth much. I did the same test on a faulty pump, it ran up a storm.

I checked the current at the green/red tracer on the fuel pump harness with the switch turned on. I got 5.6 volts, that is not correct, is it? Thanks again, esp., the quick response. flatspin

Check it with engine cranking. Have a helper crank it.

Take a reading across battery posts, engine cranking, what is the reading? Then take reading at the wire in question, engine cranking, should be close to same reading?

I had replaced all my relays under the hood and finally got power back to everything because I had pulled way to much power from my kc lights. It blew a few different things I didnt have spark or any voltage at resistor in fuel circuit.After replacing the relays I have power back everywhere. But the resistor is only reading about 2 volts. So I at least got some power bak at the resistor but Not enough. Its stays at around 2 either at the resistor or at the pump and stays the same while cranking. the voltage doesnt change while cranking either.
Why am i not getting full volts back for the fuel system?

Where is this "resistor" you're testing? My diagram doesn't show one. What's the voltage reading at the red wires going into the fuel pump relay socket? It should be 12 volts. Please advise.

[quote:bae07e45ee="James R. Weizel"]Where is this "resistor" you're testing? My diagram doesn't show one. What's the voltage reading at the red wires going into the fuel pump relay socket? It should be 12 volts. Please advise.[/quote:bae07e45ee]
The resistor is on the front fender well.

What about the voltage at the relay socket???????

My 1996 Jeep Cherokee Sport will not start. I checked the fuel pressure and there wasn't any. I checked for the humm in the gas tank and there wasn't any. I found the relay in the Power Distr. box and measured the voltage across the coil of the relay and I would see it jump to 12V when the key was turned to the run position but instantly fall to 6.5V, which I believe is not enough to pull in the relay. From the Chilton book I have it looks like the low side of the coil is connected to the ECU so I'm thinking I have a problem with the ECU. Any suggestions.