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Jeep Grand Cherokee Electrical Problems



  • I've had my Jeep for several years now and absolutely love it. Here's the problem, I hooked up a trailer harness to my adapter with the Jeep(aftermarket), the parking lights flickered then went out completely including the instrument cluster lights. I've checked all fuses and bulbs to no resolve. Can someone give a little help? I've run out of ideas.
  • Did anyone ever find out what the cause was on the 96 Grand Cherokee flickering panel lights, Headlights? Was it a ground problem?
  • My upper hose blew a 4 in. rip on 100 deg. day at idle. Some bonehead replaced relay by leaving old unit on fender and hanging new relay in the air, after plugging it in. 40 Amp connector in fan plug melted. Dorman makes replacement relay with a pigtail 4 wire crimp connector. I added thermal grease and replaced zinc/steel sheet metal screws with slightly larger stainless, to prevent loss of pressure from rusting. So far, so good.
    I did see a supplier list a bolt on fan blade for 4.0 engine. It may use a little more fuel, but you no longer have to worry about unreliable electric fan and solid state relay failure. P.S. i worked in test and evaluation of high power computer power supplies for 20 years. This application is not a dependable design for a product used in a harsh environment.
  • Judging from all the postings, many think this model is a :lemon: but my Jeep has 130K miles, 113K of which I've driven myself and never had any sort of problems at all.

    :mad: Yesterday, I walked out to run an errand and the remote wouldn't unlock the doors. Tried the spare remote and it didn't work either, eliminating the key/fob as having a dead battery. Got in, turned the key, it started up as always, ran about three seconds and died. Tried again and the normal indicators were lit but there was no reaction to turning the key; nothing. Called my mechanic who mused that it was probably the fuel pump. Didn't strike me as a fuel problem; too abrupt, felt more electrical. Grabbed my laptop, "Googled" starting problems and found one posting from what sounded like a mechanic. He made the following suggestion and it worked first try. Hoping it helps someone else here.

    :surprise: Open the hood and remove the positive battery lead. Leave it unconnected for five minutes and do nothing else. Re-install and tighten the lead. With the remote, alternately press the door lock and unlock buttons three times each. Insert key into ignition and start it up. Apparently, the anti-theft system can interpret several different events as being an attempt to steal the car and so it shuts off the fuel supply to prevent theft. Removing the battery lead causes the computer - and the anti-theft system - to re-boot and clear all faults.

    :) You can't imagine the relief I felt and how much I appreciate someone making that solution available. Hope whatever problem you're having is so easily, quickly and inexpensively resolved by someone's help.
  • go to your nearest Advance Auto, Auto Zone or the like. They will read your engine codes for free. Most likely you have a failing or failed Crank Shaft Sensor, Cam Shaft Sensor, or PCM (Power Control Module) which controls the firing of the injectors and timing. If any of the sensors are bad, the PCM will not know the position of either of the two shafts and will not know how to fire. It will then shut down the vehicle.
    It has happened to me several times.

    My friendly Advance Auto Guys helped me out.
  • Hi. We bought a 05 JGC a year and a half ago and have been experiencing the same issues as others on this forum...currently, the headlights are flickering on and off so we can drive it at night. This seems to happen more often when we use the turn signals so not sure if that is triggering it? I replaced the ignition switch thinking that might be it, but did not work.

    We were also having the transmission problems of it slipping in and out of gear. We had the transmission check by a transmission specialist and physically it was fine and they said it's probably something electrical causing it like the transmission control module. We just took it to our Jeep Dealership finally to have a diagnostic run and they said it was giving them error codes that the Transmission Control Module was bad. They replaced it a few days ago (almost $900 for parts + labor) and hasn't slipped since, but we'll see with time.

    Meanwhile, the same funky electrical issues continue (lights flickering, fan/ac/heat only works on high, etc.)

    After much, much research online trying to diagnose and fix these problems it's amazing that there is nothing anywhere from an actual Jeep tech or mechanic about this issue and how to fix it.

    Please post if you find a solution and will do the same.

  • My now stock reply to so many messages like yours is...

    it is the main wiring harness for the "bus circuit" for which your electrical system is indicating a problem. I believe there are three bus circuits.

    A qualified Jeep technician can talk to you about this and how they indicate failure of components. Jeep dealers have a sophisticated computer diagnostic that is far superior to what the small mechanics typically use. It will point to modules more often than to the actual wiring harness. In fact I am not sure if their (or any) diagnostic is designed to and can detect a faulty harness. (?)

    I replaced many modules and some twice to almost $2100. After all that I replaced two harnesses and my Jeep 06 GCL has been running as smooth as can be ever since.

    See my earlier posts for more info re wiring harness :shades:

    Recently I did replace the right rear wheel speed sensor which failed and, while I was at it, replaced the spark plugs. Typical recommended mileage for spark plugs is 40k... and mine went 105k.. wow !!!
    The gap was at least twice normal but now with new plugs with perfect gap I am still not getting any difference in MPG. go figure.

    QUESTION: has anyone noticed that after turning a corner the Jeep loses acceleration power curve until on straight path. almost like to old carbs with a float valve?
  • patriotblue01patriotblue01 Posts: 1
    edited October 2011
    bear with me, bought my jeep new in 01, this year at 130,000 miles, replaced trani with new, fuel filler pipe, brakes, (always with the brakes) fuel line, muffler, rear end, have always maintained perfectly, now my pcm is gone, have been in contact with chrysler for three weeks, ordered part, they have no idea when delivery, hundreds on back order, even after market are on back order, apparently, according to dealership(s), the 2001 jeep grand cherokee is the only one (4.0) that is vin specific, can't reprogram a used one, and chrylser dealers have none, they are saying 6 months to a year, meanwhile, I have no car....this is my third jeep, all have gone 250,000 with good routine mileage, I can't get to work, etc....their answer, buy a new one, WHY!!!! for want of a $700 part, I would have a great car, no damage, rust, I have been meticulous with this car, and yet chrysler has no part for only this year/engine... why was there no recall, should a class action be started.... my jeep is a very expensive planter...I have put $8000.00 into it since June.... what the heck can I do...HELP!
  • sorterguru1sorterguru1 Posts: 5
    edited October 2011
    Has anyone seen this? I have a 2001 Grand Cherokee limited and about 3 weeks ago I noticed the left turn signal was not working. I parked and forgot about it. The next few days I saw that it was working???? It has quit about 3 or 4 times since but always works the next day. I plan to change both the front and rear turn signal lamps but any ideas after that???
  • I am havin the same exact problem to a tee with mine. we have spent thousands trying to figure this out. mine is throwing a 1686 code, all the warning lights are lit, gauges dont work, and the electric windows only work when the car is in the accessory position, but not when the car is running..did you ever find out what the issue is or whats bad????
  • tuggajbtuggajb Posts: 646
    did you ever replace the ignition switch?
  • The problem is the PCM. Thee two screws are grounding the motherboard. Replace the 3 bolts with plastic ones and keep the PCM away from the firewall. The PCM is sending the wrong signals to your sensors that's why your having problems. Next your car will be backfiring.
  • going to try the ignition switch today. should know by tonight if that fixes the problems.
  • tried the ignition switch, still having all the same problems..anymore ideas???
  • To melbistylz, regarding the PCM. I originally posted with a intermittent, now fulltime issue with the remote door lock and gradual loss of speakers in the stereo system. I had done some research in the Jeep shop manual and suspected that the PCM was the culprit for both issues. Both the remote lock/ unlock system .and the stereo speaker wires seem to be run through the PCM. Can you respond to my suspicion and offer a solution if possible? If you need more info, please let me know. Your thoughts would be much appreciated. I can give you my email in required. Thanks!
  • There are two small screws in front of the PCM. Remove them. They are located under the 3 PCM harnesses. Also on the bolts that gold the PCM to the firewall there's one on the right side and two on the left. Remove the bottom left. Then take an old shirt and stuff it behind the PCM to prevent it from grounding out to the firewall.

    This is how far I went. After expieriencing the same electrical issues, my crank position sensor went bad all of the sudden. Then the interior lights wouldn't go off. Eventually the car backfired blew my muffler round as a balloon. I was replacing everything including the ignition switch that locked up. Distributer, roter, basically bandages, then being the computer geeket that I am figured that the PCM is sending the wrong signals. I checked the PCM and noticed that the front cover is actually the MOTHERBOARD!!! Wow even I know this should be protected by a copper box or something. Well after removing the two torque screws I turned the PCM upside down and my car started stronger and I noticed that I actually get better gas milage. Does any of this make sence? I'm kinda replying fast so I don't have time to proofread my reply.... If you need a pic let me know.
  • I know your post is over a year old but I had the same exact problem. It is a bad sensor at the door keyhole. I only have a keyhole on the driver's side. Take the door panel off and you will see wires going up to the keyhole, simply unplug it from the harness, PROBLEM SOLVED! The only downside to this is you can no longer disarm your alarm with the key, you MUST use your remote to disarm. The bad sensor was telling the car the key was there to get in, it would turn the interior lights on and disarm your alarm. Hope this helps anyone else who may be having this problem.
  • Thanks.

    I had the Transmission Control Module replaced at a Jeep Dealership to correct the slipping issue.

    As for the lights flickering issue, I had the Jeep Dealer also replace the multi switch (the turn signal/lights control) and that did the can tell the difference in how firm the new switch is compared to how loose the old one felt.

    One last note to anyone trying to fix anything on their own...make sure you buy original Chrysler/Jeep parts versus anything from AutoZone or a place like that. According to my mechanic, Jeep products don't do well with any parts that are not original Jeep.

    Good luck!
  • I too am also a female, if you put the key in the ignition and turn it forward ( don't start it) just to the on position then off three times within 5 sec. So turn forward, back, forward, back, forward, back. The check engine light will flash and the odometer will show some numbers. Write the numbers down the last number being 55. End of codes. Then google it on your computer: "jeep Cherokee Error codes (numbers) and you will find there are tons of websites that have the codes listed. Then you will know what the problem is. But the PCM is located under the hood, passenger side on the other side of the glovebox.
  • My 1996 Jeep Grand Cherokee was running fine, then one morning while taking my kiddos to school the speedometer started going crazy, bouncing all over the place. A few minutes into this the rest of the gauges started to do the same thing and it started to idle really weird like I was running out of gas, but there was still half a tank left. I did notice that the volts were reading half of what they usually do. I tested the alternator and battery, both are fine. My local dealer hasn't a clue what it could be. Can anyone please help me as to what this could be? The snow is coming soon and I have been without a vehicle for 2 months. Any suggestions would be great. Thanks for your time and Jeep wisdom!
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