- Location
- San Diego
1990 XJ, 4.0, auto, power everything.
ok so i will try and be complete as possible in describing the symptoms.
went to start the jeep this morning, turned over slowly, clicked. so i jumped it and it ran fine. turned it on and off a few times in the span of a half hour or so, no problem.
i let it sit for a few hours, go to start it, dead as a doornail. no accessories, nothing. first thing i check are battery connections, they are clean and good. all of the battery cables are about 2 years old at most and as is the battery.
threw a volt meter across the battery terminals and it read low, with the cables still connected. remove the positive cable, voltage climbs fairly quickly to between 11 and 12 volts, low but not bad. now if i put the power cable coming from the junction block bear the four main relays to the battery, it almost instantly drains the voltage back down to 1-2 volts. remove that cable, voltage climbs
my next inclination is a relay stuck open or something. so with the power cable from the relay center hooked up and the DMM connected i pull relays hoping to see the voltage rise again. no such luck. pulled all the relays i could find on the jeep. none of my accessories are the culprit. i only have a CB and amp. the fog lights are using the factory harness.
next i check the ohms from the negative battery post to the power cable from the relay center junction box. DMM beeps at me, indicating i have a short somewhere, right?
upon inspecting the wires i find on has had the insulation rubbed through. so i wrap it in tape real quick and reassemble everything, didnt fix it. i then isolate another connection at the junction block as having a short, but i have no idea where it goes, what its for or anything. so leaving that wire off the junction box, i reassemble everything again, no short at the power cable coming from the junction box anymore, so thats a good sign.
jeep still has zero lights, accessories, anything. the only thing working is the alarm. which does have a kill switch feature. it was installed by a PO so i know nothing about it, and i never use it. come to find out my key fob doesnt work for it anymore, the battery in it is good. i unhook the cables going to the alarm control box thing. now the alarm doesnt make noise, but the jeep still does nothing.
now, the only ground i have NOT replaced under the hood is the stupid metal strap going from the head to the body. would that one strap cause these headaches?
also, whats the best way to go about tracing down that short, if i truly have one. could a bad fuse somewhere cause this? i have not checked them yet, i will first thing tomorrow.
thirdly, i know every alarm system will be different but i figure ill ask, is there any way to disable the alarm easily so i can at least be able to start the jeep when i get to that point.
i will restate that i am a total wiring newb and know very little about electronics and diagnosing them. so please bare with me if i ask seemingly simple questions. sorry for the long post, i appreciate any advice.
ok so i will try and be complete as possible in describing the symptoms.
went to start the jeep this morning, turned over slowly, clicked. so i jumped it and it ran fine. turned it on and off a few times in the span of a half hour or so, no problem.
i let it sit for a few hours, go to start it, dead as a doornail. no accessories, nothing. first thing i check are battery connections, they are clean and good. all of the battery cables are about 2 years old at most and as is the battery.
threw a volt meter across the battery terminals and it read low, with the cables still connected. remove the positive cable, voltage climbs fairly quickly to between 11 and 12 volts, low but not bad. now if i put the power cable coming from the junction block bear the four main relays to the battery, it almost instantly drains the voltage back down to 1-2 volts. remove that cable, voltage climbs
my next inclination is a relay stuck open or something. so with the power cable from the relay center hooked up and the DMM connected i pull relays hoping to see the voltage rise again. no such luck. pulled all the relays i could find on the jeep. none of my accessories are the culprit. i only have a CB and amp. the fog lights are using the factory harness.
next i check the ohms from the negative battery post to the power cable from the relay center junction box. DMM beeps at me, indicating i have a short somewhere, right?
upon inspecting the wires i find on has had the insulation rubbed through. so i wrap it in tape real quick and reassemble everything, didnt fix it. i then isolate another connection at the junction block as having a short, but i have no idea where it goes, what its for or anything. so leaving that wire off the junction box, i reassemble everything again, no short at the power cable coming from the junction box anymore, so thats a good sign.
jeep still has zero lights, accessories, anything. the only thing working is the alarm. which does have a kill switch feature. it was installed by a PO so i know nothing about it, and i never use it. come to find out my key fob doesnt work for it anymore, the battery in it is good. i unhook the cables going to the alarm control box thing. now the alarm doesnt make noise, but the jeep still does nothing.
now, the only ground i have NOT replaced under the hood is the stupid metal strap going from the head to the body. would that one strap cause these headaches?
also, whats the best way to go about tracing down that short, if i truly have one. could a bad fuse somewhere cause this? i have not checked them yet, i will first thing tomorrow.
thirdly, i know every alarm system will be different but i figure ill ask, is there any way to disable the alarm easily so i can at least be able to start the jeep when i get to that point.
i will restate that i am a total wiring newb and know very little about electronics and diagnosing them. so please bare with me if i ask seemingly simple questions. sorry for the long post, i appreciate any advice.
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