alternator/ voltmeter problem?
 

Last night i was driving around in my truck, and noticed the voltmeter was down at 9 instead of 12 and the batter light was on. that was at sitting at a stopsign, then about a mile down the road going 45 mph i saw the light go off and the gauge was sitting just a hair above 9 .when i went to start the truck this morning it started fine but the gauge still sat down in the red at 9. I'm only 17 and still learning so i don't know hardly anything about the charging system yet, so i need some help diagonsing the problem.

Check or have someone check the alternator to make sure it's putting out and while you're at it load test the battery to make sure it's ok. Most Auto Zone's, O'reilly's Napas, etc will do this for you at no charge.

If you have a volt meter, check the voltage on the battery itself while it is running. This will tell you if the alt is putting out. Dont drive to far before checking it, hate to see ya get stuck somewhere.

Said he was on 17 and didn't know what to do. I figured he didn't have a volt meter or someone to help. If he had a volt meter he would have asked how to use it. Not being a smart azz that's just what I was thinking.

Well i just went out on a quick errand to walmart, about 3 miles away, when i left it was sitting at 9 still with the light on, by the time i got there tho the light was off and it was back to normal level.

It didn't come on for nothing. Have it checked before it leaves you stranded in the middle of BFE.

yeah theres a napa just down the street so i'll take it there when they open back up, they're closed today.

I think that says he is 17 not on 17 :D

A multi meter is cheap and is a must for everyones tool box. Walmart has one also if ya go there again. I think they are around $10.00 if ya go get one and cant figure it out, pm me and I'll me more then happy to explain over the phone. And you should learn these things for later on down the road anyways :lol:

I hate spelling errorss! :oops:
I agree a multi meter is must have. I had a Fluke 77 that lasted probably 20 years, but died last year. Bought a Snap On, liked the fluke a little better.
Also a decent battery load tester too. At 17 I was more interested in gas money than a multi meter though. lol

Haha yeah all my money goes to gas and insurance. Tho christmas is only a month away....

just got back from napa and the guy said the battery was at 480 when it should be at 650, he said charge it and it should be fine

The battery didn't just get low for no reason. Either, 1 battery is getting weak, 2 alternator is bad / going bad. At the most I would charge it then have it checked again soon.

Charge it?? :shock:
Napa told you that?
That's what the alternator is supposed to do!

Rabbit is right, the alt is not charging, or
the battery is not taking a charge or at least not holding it.
A rainy or snowy night with all the lights,heater, and wipers running will catch you if you don't get it now. Jmo

:D good luck to ya

Check the alternator belt.With the motor NOT running try to turn the alternator pulley by hand.If you can turn it at all the belt is loose or worn. Bill.