Alternator and Belt Dressing Question?

I sprayed some belt dressing on the drive belt in my truck. This belt is running the alternator on my Truck.

After I did this I noticed one of the idle pulley's making a noise. I did this about a year ago and then right afterwords I notice the idiot light for the battery coming on right after I started the truck up. After the truck warmed up and ran for about 5 minutes the idiot light went back out. I also have a voltage meter in the truck and I could tell that the alternator was not putting out 14 or more volts like it should. I was only getting about 12 to 11 volts according to the volt meter. And the dash lights inside the truck seemed dim. The head lights didn't seem very bright either. Once the truck ran a while the volt meter kicked up to 14 volts and the headlights and dash lights got much brighter.

I don't think I got any of the belt dressing inside the alternator. I was spraying the belt near the top of the radiator where the belt was exposed and I could get to it.

I guess the belt dressing must have worn off after a few days and the idler pulley stopped making that noise.

Well the other day I went out for a drive in the same truck and I noticed that I was not getting a bright headlight and that the volt meter was reading low again. After driving around for a bit the volt meter went back up to 14 + volts and all was fine. But each time I stopped to go shopping and came back to a cold truck the same thing happened again and again. I must have made three stops that day. It was pretty cold outside two days ago on Wed Jan 2 nd or 3 rd. 2008.

I purchased a rebuilt alternator and am going to have it installed if this keep up. Today it was a bit warmer but I noticed I was having the same thing happen. Low volts at first then it was like the alternator all of as sudden worked better.

I am wondering if it's the belt slipping or the belts too tight? Or could it be the brushes in the alternator going bad? Or could it be the voltage regular in or on the alternator? If a diode went out in the rectifier bridge it would just go out and not be intermittent now would it? I really don't know. But I am not going to fool around with this too long. By Sunday I intend to have the new alternator installed. Hopefully that will fix the problem finally.

I had Raben Tire work on it before. I broke a belt that drives the alternator while driving on the I-164 by pass around Evansville. So I went to Raben to have a new belt put on. I think that they may have put it on too lose or too tight. I went to Raben once before for a simple oil change and oil filter change and the put the wrong size oil filter on and the oil leaked out two days later. Luckily I had 2 quarts of oil with me and was able to fill the oil back up and get to another auto repair shop to get a new filter that fit right and to get another two quarts of oil. I was lucky that my oil light came on when I got low and that I just happened to have been carrying two extra quarts of oil with me that day. Or I could have ruined my engine. I would have had a quarrel with Raben Tire if that had happened. But one has to be careful these days and watch the repair men like a hawk. They make mistakes at times and you have to catch those mistakes before something really bad happens to your car like it running out of oil and seizing up the engine.

So now I just need to know what to do. It will cost $20 to have Pep boys check out the charging system but with the problem being intermittent they may not be able to figure out what's wrong. It may work fine when I get there. And it may not work right after the truck sits for a few hours and cools off again. I don't want to sit around there for 3 or 4 hours waiting for the truck to cool off so that they can figure out what's wrong.

I figured someone in here may have a clue as to what's going on.

today I added some more belt dressing and although it made the pulley louder the alternator seems to start working after only 2 minutes instead of 5 minutes. So that was a relief. I really don't think that if the brushes are going out it would work better after it got warmed up. But then again I really don't know for sure what's the problem.

I would say go to pepboys and have them check your belt.Usually your altenator just goes right out,not hanging around half bad for awhile.I would bet by what you explain it is not the altenator but just a loose or worn belt..Goodluck.....John.

I would have to agree with the belt slipping. Is this a serpentine set up or a v belt?

A belt will slip when you first "dress" it,it gets tacky as it dries,how old is your battery?i would say it may be getting weak,as stated an alternator usually just quits.The gauge in the dash is measuring volts in the battery,it is probably running off the alternator once you start driving and it is holding a little charge.if it is a serp belt with a spring loaded idler it can't be too tight i wouldn't think.You will need an amp meter to check the alternator.If it sets a couple days it will probably not start.cold weather is a battery salesmans dream.
the belt being sticky is what the noise is probably

I don't think alternators have brushes the old generators did. It is strange it works warm and not cold.

Believe it or not, but you could have a bad battery and a alternator going out or went out and your running off the battery by itself. Your getting some slight charge into the battery as you drive the truck. Go to Autozone or Pepboys and have them do a check of the battery and the alternator. They can pin point the bad item real quick. Might be a good idea to get'er done before a big freeze hits and your stuck outside in the cold trying to get the thing started.......

So what was it Moose?

So Moose, did you get the problem figured out yet?