Odd Battery charging issue (plz help)

[FrankenTruck]

New to these boards here, hoping for some late night advice before going to AdvanceAuto Parts tomarrow. Thanks in advance to anyone who can offer advice.

Ok, here is the situation...

My 92' Sport has had electrical problems for quite some time. This has resulted in me having replaced the altunater, starter, battery, battery wires, as well as hooking up a battery disconnect switch (to deal with a pesky short that would drain my battery overnight).

Thought I had my electrical woes beat till two days ago...

The voltage guage has been consistantly at the L in "NORMAL" and I never experienced any noticable problems (been like this for about 6 months or so). Last week however while driving I noticed the red battery light was on. The voltage guage was now at the N in "NORMAL". A few minutes later it jumped back to the L, then jump back to the N. This went on for a day or so, then the guage stopped jumping to L and stayed consistantly at N with the battery light staying on.

Over the next few days I noticed the guage slowly but surely getting closer to the red zone (+8). I finally went to Advanced Auto hoping it was just a bad battery. They indicated that the battery was indeed beyond simply charging and gave me a new one since I was still in warentee.

The truck started up right away, however my voltage guage still was at the N in "NORMAL". The guys at Advance looked puzzled, and indicated that my alturnator was good. The compressor was making a squeeling noise however and one of them said that I probably needed a new compressor. This sounded odd to me since I thought the compressor was just for the A/C, not charging the battery.

I left Advance Auto and have been driving for the last two days on just the battery. Interestingly enough the voltage guage started bouncing between the N and the L again, but just as before it now stays on the N and is getting weaker as can be expected.

The alturnator, starter, and battery wires are all <6 months old. All my belts are tight as well. I am going to buy a compressor tomarrow and install it as a last resort, unless anyone has a better suggestion. Can a bad compressor be causing this???

Thanks in advance... :exporange

 

[FrankenTruck]

Ps:

I think I should mention that the compressor has been making that squeeling noise for quite some time (as in, it didn't just start making that noise when this charging issue started).

Another reason why I'm hesitent to think it is the compressor, but of course I'm no mechanic (but neither is the guy at Advance Auto).

 

[elkhunter]

I don't think the compressor has a thing to do with it. Try unplugging the compressor so the clutch won't engage when you are on defrost. It won't hurt to leave it unplugged. It sounds like the drain has turned into a major draw. Have you tried pulling fuses to find the guilty circuit? Going back and forth on the guage like that has me thinking it is something to do with the headlight circuit because they are on a circuit breaker and would act like this maybe.

 

[ashleyroachclip]

If you know anything about using a volt meter...you chould be able to find your problem ....do not buy a comperssor ....that will not fix your problem ...Instead try this ....open the hood , use the meter to check battery voltage , IE you should have at the very least ...12 volts ....now with the meter still connected , start you rig ....you should have at the least 13 volts ....raise the engine speed to about 2000 rpm , ...with the head lights on , and the blower motor for the heater on full , you should have roughly 14.5 volts ....if not take the alternator back .....the voltage regulator is in the alternator , and is the only thing that will compensate for the additional load .....this internal regulator is not adjustable , and I've had them go bad on me before .....cheap alternators seem to have more problems than if you spend the extra few bucks and get the life time warranty,....if all is good here , you will need to try finding the circut that is drawing your battey down ....should do this as soon as posible ....one thought is do you have a system in your rig .....a lot of problems begin with aftermarket sound and remote alarm systems ....hope I've helped ...Ashley

 

[FrankenTruck]

Thanks

Thanks alot for the advice Ashley and Elk.

You saved me at least 300 bucks (price of a new compressor).

I'm pretty sure the alturnator is still under warentee, so im going to change that out first.

I had a sound system in before, but as of now I just have an aftermarket head unit and CD changer (the CD changer stopped reading disks about 6 months ago).

I'm going to disconnect the radio and see if that helps. How exactly do you "pull fuses to check for a short"?

Thanks again for taking the time to respond.

 

[elkhunter]

I have found open and closed circuits doing this. When you pull the fuse the load side should show 0 voltage. The power side should show what the battery shows. If it shows 0 you have an open circuit. If you check the load side with an ohm meter the light circuits will show resistance unless you pull the bulbs. The radio, for example, should not show anything with it turned off. Another method is to use the amp function between the positive post on the battery and the end of the positive cable after you have removed it. Some things will show a light draw, like a clock, but things that are turned off should not be drawing anything. If you pull the known 'always on' fuses like the clock you should not show any draw. I hope I am explaining this good enough to help. Sorry if I am not.

 

[GarSrtn]

Don't assume the alternator is good, even if you have it tested at a parts store. I've had three in various vehicles that were bad, but tested good. If looking for a short yields nothing, I would take a critical look at the alternator.

 

[jgilbs]

well if the compressor was locked up, you DO need to replace it or at least short belt your engine(get a shorter belt and route it bypassing the compressor) a locked compressor can actually cause MAJOR damage if it causes the serpentine belt to fail due to the friction it exerts on the belt by not turning. This would not cause your electrical issue. I would check the ground on the engine block to the battery if i were you, it may be corroded and need to be replaced.

 

[Biscuit42079]

Does a 2000 explorer have an external voltage regulator

 

[BKennedy]

I had a alternator do the same thing when it went bad. It was brand new out of the box when it was bad. Look on the back side and see if there is dust stuck to the plastic cover. If there is, the internals are fried and pushing out the lubricant.