XJ: what broke?? volt gauge spiked, no crank no start - Great Lakes 4x4. The largest offroad forum in the Midwest

bumpy · July 28th, 2012, 03:15 AM

so today i think the rain storm killed my XJ, i stopped at the store on the way home, turned car off went in store and came back out then tried starting the jeep and nothing... no radio, lights dont dim as theyre LED, but everything seemed weak...
got my mom to come get me and we tried jump starting but had no luck(shitty cables) damn jumper box wouldnt work either
waited a few hours went back with dad and his truck and good cables, it jump started but would only stay running with my foot on the gas pedal
i tried driving it home, made it a half mile and it died, i noticed that the voltage gauge was spiked at like 19++ which isnt good and makes me think bad voltage regulator?
do XJs have a voltage regulator? ive never seen it!? what could my problems be?
bad alternator?
bad voltage regulator?
bad ecm?
bad pcm?

when i wake up im gonna pull the alternator and battery and go get them tested at autozone, get the battery load tested.. i have a spare alternator here and im gonna swap that back in and have it tested at autozone while im at it... what else should i swap out and check out first??

i have the jeep basically traded for as of right now and it needs to be running by noon sunday at the very latest!!! it hasnt broke down on me in a long ass time, maybe its a sign to not get rid of it?? last time it was almost sold/traded for 2 weeks ago, the waterpump went out

this time im hoping to trade it for a 2002 chevy silverado ext. cab z71, but that will only happen if the Jeep is running and driving sunday!!

HELP ME PLEASEEEEEEEEEEEEEE!!!

but seriously any help is greatfully appreciated!

bumpy · July 28th, 2012, 01:12 PM

45 views and no suggestions?? cmon guys please, i need idears??

tw1st3d5 · July 28th, 2012, 01:33 PM

Sounds like a voltage regulator which I believe is built into the alternator. It could have killed the battery as well or the bad battery could have toasted the vr.

tw1st3d5 · July 28th, 2012, 01:33 PM

Did you get them tested?

bumpy · July 28th, 2012, 02:06 PM

in the process of pulling everything now, alternators a bitch to get to when its in the vehicle... sooooo much easier when the motors on a stand

Rob the plumber · July 28th, 2012, 02:26 PM

Voltage is regulated by the computer, not regulated inside the alternator.

ajmorell · July 28th, 2012, 03:01 PM

Quote:

Originally Posted by Rob the plumber

Voltage is regulated by the computer, not regulated inside the alternator.

Correct, if the voltage regulator shit the bed you'll have to replace the whole PCM

Sent from my DROID BIONIC using Tapatalk 2

bumpy · July 28th, 2012, 05:25 PM

alternator tested good battery tested bad, i have an extra battery here from my jetta same size and everything gonna throw it in and hope that was the only problem... i fear otherwise though...

wave_crusher · July 28th, 2012, 05:39 PM

hook up jumper cables....or a new battery.

when you turn the key "on" what lights come on the dash? after you try to start it, what lights are still on? It's probably either the battery, or the computer; just like everyone else says.

bumpy · July 28th, 2012, 05:46 PM

what lights show up out of the ordinary is that the check gauges one shows up when trying to start but nothing else was abnormal... i have a feeling its the PCM as well but i dont want it to be..

wave_crusher · July 28th, 2012, 06:34 PM

what does it do when you try to start it? clicks or just nothing at all?

ajmorell · July 28th, 2012, 06:59 PM

Check and double check all your grounds. My Jeep acted funny when the battery to chassis ground was really loose, I also thought it was the alternator

Sent from my DROID BIONIC using Tapatalk 2

bumpy · July 29th, 2012, 10:48 AM

thanks for your help ajmore

Jeeper52 · July 29th, 2012, 01:31 PM

Quote:

Originally Posted by Rob the plumber

Voltage is regulated by the computer, not regulated inside the alternator.

Thats what I thought

July 28th, 2012, 03:15 AM	#1
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	what broke?? volt gauge spiked, no crank no start so today i think the rain storm killed my XJ, i stopped at the store on the way home, turned car off went in store and came back out then tried starting the jeep and nothing... no radio, lights dont dim as theyre LED, but everything seemed weak... got my mom to come get me and we tried jump starting but had no luck(shitty cables) damn jumper box wouldnt work either waited a few hours went back with dad and his truck and good cables, it jump started but would only stay running with my foot on the gas pedal i tried driving it home, made it a half mile and it died, i noticed that the voltage gauge was spiked at like 19++ which isnt good and makes me think bad voltage regulator? do XJs have a voltage regulator? ive never seen it!? what could my problems be? bad alternator? bad voltage regulator? bad ecm? bad pcm? when i wake up im gonna pull the alternator and battery and go get them tested at autozone, get the battery load tested.. i have a spare alternator here and im gonna swap that back in and have it tested at autozone while im at it... what else should i swap out and check out first?? i have the jeep basically traded for as of right now and it needs to be running by noon sunday at the very latest!!! it hasnt broke down on me in a long ass time, maybe its a sign to not get rid of it?? last time it was almost sold/traded for 2 weeks ago, the waterpump went out this time im hoping to trade it for a 2002 chevy silverado ext. cab z71, but that will only happen if the Jeep is running and driving sunday!! HELP ME PLEASEEEEEEEEEEEEEE!!! but seriously any help is greatfully appreciated!

July 28th, 2012, 01:12 PM	#2
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	45 views and no suggestions?? cmon guys please, i need idears??

July 28th, 2012, 01:33 PM	#3
tw1st3d5 Senior Member Join Date: 10-12-09 Location: Berrien Springs, MI Posts: 991 iTrader: (16)	Sounds like a voltage regulator which I believe is built into the alternator. It could have killed the battery as well or the bad battery could have toasted the vr.

July 28th, 2012, 02:06 PM	#5
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	in the process of pulling everything now, alternators a bitch to get to when its in the vehicle... sooooo much easier when the motors on a stand

July 28th, 2012, 02:26 PM	#6
Rob the plumber Licensed master plumber Join Date: 06-14-06 Location: New Baltimore, Michigan Posts: 4,582 iTrader: (27)	Voltage is regulated by the computer, not regulated inside the alternator.

July 28th, 2012, 05:25 PM	#8
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	alternator tested good battery tested bad, i have an extra battery here from my jetta same size and everything gonna throw it in and hope that was the only problem... i fear otherwise though...

July 28th, 2012, 05:39 PM	#9
wave_crusher I'll Direc your TV Join Date: 01-20-09 Location: Big Rapids, MI Posts: 3,793 iTrader: (15)	hook up jumper cables....or a new battery. when you turn the key "on" what lights come on the dash? after you try to start it, what lights are still on? It's probably either the battery, or the computer; just like everyone else says.

July 28th, 2012, 05:46 PM	#10
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	what lights show up out of the ordinary is that the check gauges one shows up when trying to start but nothing else was abnormal... i have a feeling its the PCM as well but i dont want it to be..

July 28th, 2012, 06:34 PM	#11
wave_crusher I'll Direc your TV Join Date: 01-20-09 Location: Big Rapids, MI Posts: 3,793 iTrader: (15)	what does it do when you try to start it? clicks or just nothing at all?

July 28th, 2012, 06:59 PM	#12
ajmorell Senior Member Join Date: 01-22-07 Location: Santa Fe, NM Posts: 3,022 iTrader: (16)	Check and double check all your grounds. My Jeep acted funny when the battery to chassis ground was really loose, I also thought it was the alternator Sent from my DROID BIONIC using Tapatalk 2

July 29th, 2012, 10:48 AM	#13
bumpy jeep>volkswagen Join Date: 11-14-05 Location: troy Posts: 877 iTrader: (19)	thanks for your help ajmore