headlights killing everything 1hour from home

[scorpio_vette]

ok, so i've mentioned in another thread that when i turn my headlights on, several of my gauges go wacky. well now finally this afternoon, the waggy wouldn't start on me anymore. put a set of jumper cables on, and litterally "the second" you get the cables connected, it starts right up without problems and stays running after that. but it won't start by itself anymore. i replace the starter solenoid, but it still won't do anything. it acts like the battery is bad. i used a voltimeter to watch the battery. with everything off, the battery has around 11 volts. with the jeep in idle, it has around 12.xx volts. but the second i turn the headlights on, the voltage starts steady dropping and will not recover unless i turn the headlights off. then it recovers fine.

what can i check that could be causing the headlights to kill everything in the vehicle???

why will it not start by itself, but with jumpers it starts perfectly???

i'm 1hour away from home, and now happens. this sucks.

i can fix just about anything on cars, but i'm horrible at diagnosing electrical issues. so any help would be appreciated.

[Millerluck]

How old are the cables?

Got good clean conections at the clamps?

Larry

[Ristow]

How old are the cables?

Got good clean conections at the clamps?

Larry

yep,clean the cables,and battery posts. might have a junk battery.

[scorpio_vette]

cables are decent, i also cleaned up the cable ends and the fender part where the starter solenoid bolts up to, and the battery is not even a week old. it just started doing it this afternoon. this entire last week the waggy has started better than any vehicle i've ever owned. then all of a sudden this afternoon we stopped at a pizza place and it wouldn't start. had somebody jump me, and it fired up instantly. so i drove it to the inlaws house, and now it won't start again. it starts fine on jumpstart, but not by itself.

and the charging voltage seems to stay normal until you turn the headlights on. then everything get's screwed up and the voltage starts going down. i have no clue where to start on this problem.

[aerocorey]

Ground problem. How are you connecting the cables? If you're hooking battery (-) to battery (-) your electrical system is using the other vehicle as a ground. Clean them all, body, battery, engine. Check the cables, use a wire brush and maybe some di-electric grease. Clean the (+) terminals on the battery and solenoid as well. Check the connection from your solenoid to your alternator, clean that too. Check the regulator connector on your alternator, if it's questionable you can get a new plug for $2 at any Mc Parts store. Replace the terminals on your headlight grounds and clean the body where they attach. Worst thing that'll happen if you do all of this is you'll be able to rule out a grounding problem and you'll have performed a good bit of preventative maintenance.

Your battery is probably toast by now even if you do fix the problem so you'll need to be jumped at least once even if this does fix your troubles. This falls into the category of "freaky deaky electrical gremlins". That's usually a grounding issue. All the crap I mentioned above with the exception of the headlight grounds fixed Herc up good when she was giving me all sorts of problems. Good luck.

[letank]

if you have a model w ammeter 86 and older.... then the ammeter may be shorting... just bypass it by connecting both wires on the same ammeter post.... for the quick and dirty.... REMEMBER disconnect the battery to avoid JEEPBBQ.

then do the bypass at the alternator battery. You will be surprised by how much brighter your headlights are....

Happened to me many years ago... the parking light did not do it... but the big draw of the headlight killed the power supply

[shimniok]

ok, so i've mentioned in another thread that when i turn my headlights on, several of my gauges go wacky. well now finally this afternoon, the waggy wouldn't start on me anymore. put a set of jumper cables on, and litterally "the second" you get the cables connected, it starts right up without problems and stays running after that. but it won't start by itself anymore. i replace the starter solenoid, but it still won't do anything. it acts like the battery is bad. i used a voltimeter to watch the battery. with everything off, the battery has around 11 volts. with the jeep in idle, it has around 12.xx volts. but the second i turn the headlights on, the voltage starts steady dropping and will not recover unless i turn the headlights off. then it recovers fine.

Sounds a lot like your alternator isn't able to keep up with the extra current draw of the headlights. Can you duplicate the problem by turning on the heater motor, ac motor, and other accessories?

Also, you should be seeing 13.8V at the battery at idle give or take a few tenths (or at least, at fast idle). If not then there is an alternator problem.

11V on the battery is only just enough to start a vehicle. Less and you will have a hard time. After running the rig, your battery voltage should be around 12.0-12.5V

Michael

[aerocorey]

Sounds a lot like your alternator isn't able to keep up with the extra current draw of the headlights. Can you duplicate the problem by turning on the heater motor, ac motor, and other accessories?

Also, you should be seeing 13.8V at the battery at idle give or take a few tenths (or at least, at fast idle). If not then there is an alternator problem.

11V on the battery is only just enough to start a vehicle. Less and you will have a hard time. After running the rig, your battery voltage should be around 12.0-12.5V

Michael

This is what I thought with mine too for the same reasons, that's why I threw over $100 worth of alternators at it before I cleaned my grounds and connectors. I was like 100% certain that I had a bad regulator. I was seeing like 8V at times on the voltmeter. I had to be jump started, turn off EVERYTHING, and keep my foot on the gas just to keep running. The fact that it would stay running when I leaned on the gas made me think it was a bad belt so I changed that too along with the pulley. After cleaning all the contacts up real good and changing a few cables I put the original alternator back in and it worked fine.

Not saying you're wrong, just saying alternators are expensive and it can't hurt anything to change a few connectors, knowwhatimean?

[DanHS]

Sure the headlights aren't shorting somewhere and zapping all the power? Possible that at one point the headlights were rewired without a fuse, and somehow manage to not melt anything, yet. Grounds are a huge pain when you can't find some corroded connection hidden somewhere. Did you trace the wiring from the alt up to the fuse block?

[scorpio_vette]

ok here's what i got so far. i decided to push my luck and drive the waggy home last night after jumping it again. well wouldn't you know it, i must have done something right to earn this jeeps trust already, cuz just like my other 2 jeeps, this one didn't let me down and got me all the way home before it decided to give up. so i pulled the battery last night and put it on the tester. the tester determined the battery was bad and had 0 CCA. well since that's the only battery i have until i can go back to the store today, i decided to put it on the charger and force it to work for now. so while the battery was on the charger, i started looking over the waggy very carefully.

1) alternator belts were getting loose. after looking a little closer, i noticed the the alternator pulley wasn't in line with the other pulleys. after looking a little closer (remember i've never had a waggy or anything similar, engine wise, so i have to figure this stuff out first), i noticed that the alternator was installed incorrectly. the top of the alternator was missing the long spacer bushing, so it was sliding back on the bolt, and the bottom was mounted between the engine and the bracket insted of between the bracket and the radiator. so i took the alternator out, cleaned the connections as good as i could, grabbed some XJ and TJ swaybar endlink bushing sleeves (the little metal inserts) and used those as spacers for the upper bolt. then i put the bottom of the alternator on the proper side of the bracket and bolted everything back up and tightened it. the belts are much much better than before, but not as much as i'd like. i'll need new belts.

i also disconnected the battery ground cable from the body and engine and wire wheeled all contact points on the cable end and engine/body. i pulled one of the headlights, but the wiring looked un-touched, so i left that alone for now. i looked under the dash some more. there is a little harness that goes from the digital clock, to a plug that splits off into 2 little harnesses. and one of those harnesses was hanging down towards the A/C controls, and had a blue and red wire (i think. i'll verify later) that were both cut. so i have to figure out where those 2 wires go.

then i put the battery back in and decided to try it before going to bed. it started right back up just like before, the headlights were brighter, the ammeter (had to figure out what the hell that was for first. never seen one) seems to be doing what it's supposed to now, and the gauges didn't go haywire (at least for now). and i got 2 of the dash lights to work. now i just gotta get the gauge lights to work. lol

well slowly but surely it's getting there. well i gotta go now. if it starts, we'll drive it back to the inlaws for their easter church thingy. if it doesn't start, we'll take the wifes TJ. lol

later guys and thanks for all your help.

(i'm a little disapointed that none of you guys even thought of mentioning that the alternator wasn't installed properly. LOL)

[aerocorey]

You're on track now. These things are all uphill until you get ahead of them. Once you're ahead of them all you gotta do is put in enough effort to stay ahead and you'll be in good shape.