• ODT Gun Show this Saturday! - Click here for info and tickets!

Battery/Alternator Question

CliffB

Default rank <4500 posts
ODT Junkie!
74   0
Joined
Jun 27, 2011
Messages
4,017
Reaction score
1,944
Location
Stockbridge
Alright so today while sitting at a red light an hour from home my battery light came on on the dash. As soon as i accelerated away from the light the dash light turned off. Once again when i returned to a stop the light came on again. Progressively it went from only at a stop to intermittently while driving. I drive for a few miles and stop and check the battery post(4 week old battery). The negative post was ever so slightly loose. Used some pliers and tightened it up. Kept driving to my destination which was 30-40 minutes from home. At that point i used a socket and tightened both posts down tight. Continued to drive the rest of the way home on 285 in stop and go traffic running only my headlights and no problems at all but the dash light was still coming on and going off.
So now i am home and i just hooked the charger up to the battery and it is reading 12.2 amps. While driving home i hooked up the SCT and the battery voltage spiked at 12.31 and never went below i believe 11.48 with lights on and truck on. Correct me if i am wrong but there is no way possible i could have driven an hour home and almost 30-40 miles without dropping the battery below 12.2 if the alternator was bad? If the alternator was bad an i was in fact driving home on battery power alone then by all reason i should be much below 12.2 and possibly not even made it home. My thoughts are i just screwed up by not tightening the ground post all the way and now the truck is still throwing distress signals even though it has been corrected. Should i take the negative cable off and let the codes reset or just let it charge on a 2 amp charge overnight and recheck in the morning? Thoughts please.
 
Yeah, seems like the alternator isn't putting out until the rpms come up. Could be a loose belt but probably not with the serpentine. I use a little belt dressing on my stuff, but it won't fix a bad alternator.
 
With everything tight and hooked up, put a multi-meter on the battery terminals. At idle, you should have 14+ volts. If its less and then increases when you raise your engine rpm, you either have a defective battery or a bad regulator (alternator).
 
I've seen batteries drop a cell and pull down the entire system making it look like a bad alternator. Another thing you can do is crank it and pull off one battery terminal. If she dies, you've got problems with the charging system.
 
With everything tight and hooked up, put a multi-meter on the battery terminals. At idle, you should have 14+ volts. If its less and then increases when you raise your engine rpm, you either have a defective battery or a bad regulator (alternator).

cough don't own a multimeter cough I know, I know i'll take care of that immediately.
 
Back
Top Bottom