parasitic power loss from instrument cluster 96 GC
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parasitic power loss from instrument cluster 96 GC
my '96 GCs battery has been dying when it sits for a couple days.. so i decided to do some testing... bridged my multimeter into the positive battery cable/post, found a 160ma drain...
so then i reconnected the cable and i went to the power distribution box under the hood, started pulling fuses and probing them with my multimeter.. a 50 amp fuses circuit was drawing 160ma
checked a wiring diagram and found this leads to the internal fuse box under the passenger side dashboard.. so leaving the 50 amp fuse out i would remove a row of fuses from under the dash, remembering where they went, then checking the PDC for the draw to narrow down the cuplrit
i found a yellow 20a fuse to be the culprit, with it removed there was no drain on the battery, and all internal electronics worked except the instrument cluster.. back of the fuse cover states it went to the cluster.. so theres the culprit
what i need to do now is try to figure out what could cause the instrument panel to short out and cause this drain, none of the gauges work with that fuse removed and they all appear to work with it installed, though ill check again to be sure
one other symptom that may or may not be related.. it seems the overhead cabin lights will not turn off while driving, but do turn off when the key is removed (and there is no draw from the battery when shut off)
anyhow... what should i do from here to find the short?.. how would i go about removing the instrument cluster to check the draw and continuity of the connections? since it seems this is what i must do now...
well, thanks in advance for any help given.
so then i reconnected the cable and i went to the power distribution box under the hood, started pulling fuses and probing them with my multimeter.. a 50 amp fuses circuit was drawing 160ma
checked a wiring diagram and found this leads to the internal fuse box under the passenger side dashboard.. so leaving the 50 amp fuse out i would remove a row of fuses from under the dash, remembering where they went, then checking the PDC for the draw to narrow down the cuplrit
i found a yellow 20a fuse to be the culprit, with it removed there was no drain on the battery, and all internal electronics worked except the instrument cluster.. back of the fuse cover states it went to the cluster.. so theres the culprit
what i need to do now is try to figure out what could cause the instrument panel to short out and cause this drain, none of the gauges work with that fuse removed and they all appear to work with it installed, though ill check again to be sure
one other symptom that may or may not be related.. it seems the overhead cabin lights will not turn off while driving, but do turn off when the key is removed (and there is no draw from the battery when shut off)
anyhow... what should i do from here to find the short?.. how would i go about removing the instrument cluster to check the draw and continuity of the connections? since it seems this is what i must do now...
well, thanks in advance for any help given.
#2
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Seems like you're already on your way to answering your own question. Not sure if the dome lights are on the same line as the cluster, try pulling the fuse and see if the lights turn off?
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see.. thats just it... the fuse for the cluster is out and the lights are stuck on.. so it leads me to believe theyre unrelated
you know.. the one door does need new hinge pin bushings.. its sagging, perhaps the door isnt making proper contact with the switch and theyre in a "door open" mode?... ill look into that more
as for the instrument cluster, ive found a tutorial online for removing it.. not too difficult, but how do i go about finding the problem?.. should i test the gauges for continuity, or resistance?.. check the continuity of the wiring?.. not sure how im supposed to test these
you know.. the one door does need new hinge pin bushings.. its sagging, perhaps the door isnt making proper contact with the switch and theyre in a "door open" mode?... ill look into that more
as for the instrument cluster, ive found a tutorial online for removing it.. not too difficult, but how do i go about finding the problem?.. should i test the gauges for continuity, or resistance?.. check the continuity of the wiring?.. not sure how im supposed to test these
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been doing some more investigation into jeep wiring.. it appears the relay which switches the interior lights on an off is in fact on the same fuse as the instrument panel... so with the fuse removed the lights stay on while driving.. with the fuse in they dont even work, but then theres that 160ma draw... instruments all work with the fuse in...
so this leads me to believe my draw is in fact with the lighting system and not the instrument cluster...
drivers side switch is busted, stuck in the closed position, but i dont think this would cause a problem.. but reguardless it does need to be replaced.. ill use a universal fit switch from napa for this
so.. i guess my next goal is to locate the relay for these switches to turn them off when the doors are closed, maybe test the continuity of all the door switches to make sure one of thems not shorted out
i must say.. i hate having to do faulty wiring jobs on any vehicle.. but my new multi-meter is making this soooooo much easier
so this leads me to believe my draw is in fact with the lighting system and not the instrument cluster...
drivers side switch is busted, stuck in the closed position, but i dont think this would cause a problem.. but reguardless it does need to be replaced.. ill use a universal fit switch from napa for this
so.. i guess my next goal is to locate the relay for these switches to turn them off when the doors are closed, maybe test the continuity of all the door switches to make sure one of thems not shorted out
i must say.. i hate having to do faulty wiring jobs on any vehicle.. but my new multi-meter is making this soooooo much easier
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Hahah well you're doing a really good job for not liking it so much. I would start by fixing what's broken (the door) and go from there, it does sound like you have a short somewhere.
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one thing i forgot to mention that makes me a bit curious.. the windshield wipers work, but only full on or full off.. theres no delay, no intermittent control, none of that works... this coupled with the lights make my thing perhaps the BCM is fried.. but im not too familiar with this component, so id like to hear from someone who has dealt with bad BCMs to verify before i remove it or replace it... also, the ABS light is on... so im not sure if that means something or not.. but i heard the BCM controls that too
Last edited by animus_divinus; 01-10-2012 at 08:45 PM.
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one thing i forgot to mention that makes me a bit curious.. the windshield wipers work, but only full on or full off.. theres no delay, no intermittent control, none of that works... this coupled with the lights make my thing perhaps the BCM is fried.. but im not too familiar with this component, so id like to hear from someone who has dealt with bad BCMs to verify before i remove it or replace it... also, the ABS light is on... so im not sure if that means something or not.. but i heard the BCM controls that too
Have you fixed your door switches yet?
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the switches seem to work fine... ill check again tomorrow and test some other components
i mentioned the wipers have no intermittant control, either full on or full off.. ive located the relay for the wiper in the PDC... but how would i go about testing this to see if it functions?... which pins need to have continuity, resistance... theres 5 of them so its hard to tell what to do to test it...
besides the battery drain, the lights that wont shut off and the lack of intermittent wiper control everything else seems to work fine, including the instruments... so what else could i pull in an attempt to narrow down whats causing the problem?... the lights are just an annoyance right now and not causing a drain unless fuse #7 is replaced in which case they dont come on at all... so this is leading me to believe somethings wrong with the switch, wiper relay, or something common between them on the cicruit.. but since everyone else works it leads me to think the BCM is OK
i mentioned the wipers have no intermittant control, either full on or full off.. ive located the relay for the wiper in the PDC... but how would i go about testing this to see if it functions?... which pins need to have continuity, resistance... theres 5 of them so its hard to tell what to do to test it...
besides the battery drain, the lights that wont shut off and the lack of intermittent wiper control everything else seems to work fine, including the instruments... so what else could i pull in an attempt to narrow down whats causing the problem?... the lights are just an annoyance right now and not causing a drain unless fuse #7 is replaced in which case they dont come on at all... so this is leading me to believe somethings wrong with the switch, wiper relay, or something common between them on the cicruit.. but since everyone else works it leads me to think the BCM is OK
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