02 Jeep Grand Cherokee Limited/ intermittent electrical issues
My 02 Grand Cherokee Limited started experiencing some type of electrical problem the other day. The gauges will go go up and down, the relays will all click on and off and the idle fluctuates but continues to run. After a whil, it will stop and everything will start working properly. Then when I hit a bump or make a turn it may happen again. It is clearly a short or bad ground but I am trying to isolate the possible location. The problem seems to effect all electrical functions of the vehicle simultaniuoulsy, however, the vehicle does not quit running. Sometimes all of the gauges will work until I try to turn on the headlights or heater. Then everything will turn on and off very rapidly. Today on my way to work it was working fine. I stopped for a coffee and when I returned to the jeep it was messed up again and I could not turn on the lights or the heater without causing the problem. When I turned them off the gauges returned to normal operation and I went on my way. I decided to pull over and check some things to see if I could get it working again. as I came to a stop and put the vehicle in park the heater came alive and it seemed as if everything was working properly. When I got out and looked at the vehicle I noticed that the driver side headlight was not lit up and also the driver side turn signal did not work at all when I flipped the switch, no signal, no sound, no indication. Also at that time the RPMs were fluctuating. It may be like this for a while and then later it will either stop working completely or start working completely. Yesterday I noticed that the situation was reversed. ALl of the driver side lights worked and the passenger side was out. I pulled the bottom of the dash apart and vigerously inspected the wiring lol. I hit things and manipulated wires while it was working and could not get it to fail. I stopped for a cigarette break and while I was standing next to the vehicle it started malfunctioning. I could not get it to stop as I went through the harnesses and bundles again. About 10 minutes after I finished I was sitting in the driver seat contemplating my next move when everything came alive and started working again. I am feeling like this situation has got to be related to the wiring/ground for dashboard components. I just can not seem to find the faulty connection. I also have been unable to locate the common ground for the dash. The jeep has a 4.7l engine, fully loaded. The stereo system from when I purchased the car is aftermarket. The power for the stereo is run directly to the battery and is never effected by any of these symptoms. I have also noticed that the headlights are aftermarket HID lights. I have tried disconnecting them from the power to see if the problem persisted and it did not make a difference.
Thought I would leave this here in case any web searchers like myself have the same type of problem. I think I have fixed it! I pulled out the center console and found that the grounding point for the BCM (body control module) was missing the nut that secured it to the post. How this happened? Who knows... The issue here including the abnormal RPM flux, believe it or not, was all because the BCM ground was just sitting on the grounding post and wiggling around. That means that there is at least a decent chance that if you have this problem and go through the same steps that I followed and did NOT find a solution. The likely cause is an actual BCM malfunction.
where is the BCM ground located as I am having this issue also.
While researching a similar issue, I found this image of the ground points. These points are located in close proximity to the Airbag Control. Disconnect the negative lead from the battery to prevent inadvertent deployment of the airbag system when working with these grounds.
Just imagine if the problem was as simple to fix as: The alarm siren is situated behind the front wheel arch protective cover. Its too low on the truck, it gets wet and damp regularly. It shorts and causes a problem in the BCU! This causes all of the symptoms described. It also causes a battery drain. Take the siren off the connector, wrap the connector in rubber glove and tape it. The siren is scrap due to the continued soakings. The BCU May be damaged and need replacing. I won't guarantee a fix but I'm fairly confident. Phil
Sorry , BCU should say BCM. Phil
So after a year of horrid electrical problems which I have noticed others posting the same or similar complaints on these sites got me thinking. How could I lose power randomly or Sporadically through out my jeep. No one had answers as each occurrence was different. So through many mechanics and idiots i came across a guy who showed me where all the problems lie. So if your door lights, windows, door sensors, key fab (due to electrical inside) do not work..... please check the wire harness in the boot in the front door jams. Per Chrysler half of these wires are the correct gauge and the other half are to big. So in mu case more than half of the wires were severed over time cause sporadic connections all throughout my jeep. When the doors were closed they said they were open. Lights stayed on all night (replaced my battery 2x) windows sometimes or never go down..... on and on. I called Chrysler and they said I was the end of the line and there was no help for me because i have a vehicle over 13 years old. So the only fix he could come up with since jeep will not recall the harness A**holes, I am stuck with soldered wires. If they weren't such a**holes and recall the gauge we could all live happy lives instead of dumping tons of money into these hunks of steel. I did not give in and replace half of the parts sensors/motors/relays and whatever else people have done to solve this huge electrical ordeal that has consumed my life. Anyways..... have seen post about a yellow or colored wire in that boot that is listed as the issue but please just pull them out as far as possible and see for yourself all the severed wires that are caused by the door closure alone. I hope this helps somebody. Oh and I am going to keep calling jeep to complain as they said they haven't had enough complaints on this issue to deserve a recall. I heard this is also common in Dodge vehical obviously and Ford. Just fyi
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