Hello all, I have a '96 classic, idk how long this has even happening but, I just noticed that when I have the heater/ac on along with the radio and headlights, the voltage gauge drops to about 10-12 and won't rise above that unless I turn off 1 of the 3, when just the radio and or light are on, it stays on 14v, could this be the blower, alternator or regulator? Thanks for any help

 

Quite likely it's your alternator. I had similar problems before replacing my alt. Now voltage is fine at idle.

 

Not to disagree with Dan, on my jeep low voltage is the first sign my belt is loose/slipping. It doesn't always make noise.

I recently went round and round with a new belt from O reilies...was chirping also...until I ran a hose and dish soap on it, (both sides with it idling), then water for a good while.

I just mention that goofy deal because it really had me flustered. New and tight and not working. I guess it had some sort of coating...the soap (and rinse)took good care of it.

 

I also have a high pitched squeal at first startup for less than a minute, it does t get louder when I press the gas pedal, so I don't know if its the belt or not connected to this problem, idk how to upload a video so..... I'll do a voltage test later at work and let you guys know the results

 

Id also take a volt - ohm meter to your battery terminals and check to see if the voltage read there matches what the gauge in the cluster says. Mine as of right now still jumps down to 10-11 volts when I have my KC's on, head lights, and AC on. If you get a reading from the volt - ohm meter at the battery though it reads 14.2 volts. This is with a new alternator in there as well. So something is wrong with my gauge or gauge wiring. Just a thought to try before spending too much time looking other places.

 

I'm gonna bet the belt is slipping on the alternator pulley. It slips after you start it because the alternator is working harder to bring the battery back up after the starter motor ran.

Agreed on not trusting the dash voltmeter, measure at the battery terminals and see what you have.

 

Thanks a lot, I'll keep ya's posted!

 

Does sound like a loose belt. When you start it you take a bit from the battery. As soon as it starts up it works hard for a minute to top it back up.

I bet if you turn on the headlights and blower as soon as it stops it will do it a bit more again.

The only time I did a video was to post it on U-tube, and post the link. (others know some sort of "black magic" . Anyway, just tightening the belt so it doesn't squeal might be easier, or washing w/ dish soap and rinsing well.

I guess it should take some effort to twist it 1/4 turn.

The alternator works harder when the magnetic field in the spinning rotor is making more current in the outer stator windings. The regulator controls that field, based on the voltage.

 

Ok 1 more thing to add, just throwing this out there, I started to do the cap, plugs, wires and rotor, the guy at advance gave me the wrong cap and rotor, so I did the wires and plugs, the old ones were gapped at .50-.60 I gapped the new ones at the proper gap of .35, sounds crazy but could any of this have something to do with it? It was that night that I had noticed the drop, but I'm guessing either the belt or the alt itself, just hoping for a cheaper out lol

 

Start 'er up, turn on the lights, blower, rear defroster, radio... then measure your voltage at the battery and see what you have. Then shut it off and feel the alternator pulley. It'll be quite hot if the belt is slipping on it.
I doubt the cap/rotor or plug gap is related.

 

Howdy Chuck! Boy am I slow!

Nope. It's just loose it sounds like. And yep, .35 is correct. That get's a little bigger each minute though. I check/adjust mine a couple times a year at least.

 

Hiya Don!

I'm ashamed to admit I haven't changed or even checked my plugs for probably 60-70K miles. Still runs just fine so I don't think of it. Probably should do that, lol.

 

I did the same thing a couple years ago. Finally with a rough idle I found them over .45.....I actually even bought new ones!

Great tip in the hot pulley by the way. We are so lucky to have you here!

 

Ok, I just put the meter on it, the gauge hovers around 12v but the meter reads 13.68-13.70

 

Ya, this is what I'm experiencing. Soon I will be pulling my gauge cluster and cleaning the electrical connector behind the gauges. Along with this making a grounding cable for the gauge cluster that Cruiser54 suggests to do. Ill let you know if that helps.