Hey guys, last night I started-up the truck. I noticed that the voltmeter was bouncing quickly from the 'A' and 'R' in NORMAL. Any use of electrical accesories would dip the voltmeter, dim lights, and the RPM's would fluctuate. Also, there was a whining noise....almost supercharger-like sound coming out of under the hood and it varied with engine RPM.

I turned it off. I tried using the locks and they would barely move. I turned on the lights and they were really dim. Then I cranked the truck up and it started normally and everything went back to normal.

Now, could this be signs of an alternator going out? The battery isn't even a year old and i have new ground/power wires. I'll double check grounds, but I dont have the truck right now. Anyway, sorry for the long story, but what do you guys think?

 

Those symptoms can be caused by the alt or the battery going bad, or a bad ground.

I would get both them both tested just to rule them out. If they're ok, I would check for a bad ground or maybe a loose wire where the alt feeds into the starter relay.

Even a new battery can have problems - that's why they carry warranties.

 

I would think it has a weak alternator or battery. But when you mentioned that you shut it off and the lights were dim, that makes me wonder. Normally if your lights are dim and your power door locks are barely working, then that battery certainly couldn't crank over an engine. Maybe you had a loose ground, and when you hit the key to start it, that ground could have made an arc and got connection.

 

andy, I will check for loose wires, thanks

handyman, i was puzzled too as when the lights were so dim, why the truck cranked normally...i was expecting a slow crank.

Hmm... really does sound like a loose wire somewhere. Thanks, guys i'll get back to ya.

 

Please do, this one has me stumped lol.

 

Whatever the heck it was....its fixed, lol. I double checked the grounds on the fender, the block, and the battery itself. All tightened, just the battery had little corrosion on it, but i cleaned it off.

 

check the belt and see if it was slipping. It will looked glazed if it was.
If it was really cold, like -10, i've seen weirder thing happen because the battery juice was frozen. Its best to turn on the headlights for a minute to help the battery thaw I was told and its always worked fine for me.
Happy New Year.
Tim

 

I had a similar problem the other night. Gauge was low, and then all of a sudden it made a wierd noise and then it was fine. I ignored it and went on with driving.