hfdff

I have a 2000 chevrolet silverado with a 5.3lt engine. Here's my problem the other morning I started my truck and noticed that it was kind of slugish to start but it started. While taking the kids to school I noticed that the battery light came on in the message center and volt gauge read approx. 10 volts. Put my volt meter on the battery with truck off and read approx 11 volts, turned truck on battery voltage did not increase and reved up the engine and nothing. My inital thought it was the alternator.

Take alternator to the local auto store and it tested fine. Tested the battery told me that I had a dead cell. I put the new battery in it starts up but the battery light on and volt gage read about 10 volts. Put my meter on the battery it reads 12 volts. Rev up the engine and after a little bit battery light goes out and volt gauge reads 14 volts. I think problem solved.

I go pick up the kids start the truck and Battery light comes on and volt gauge reads approx 10 volts. After driving for about 20 min light goes out and gauge reads. 14 volts. Same thing happened this morning. So before I pick up the kids today I check the voltage on battery it reads 12 volts turn the truck on battery light comes on and gauge reads approx 10 volts. Check the voltage it reads 12 volts rev up the engine and voltage stays at 12 volts. Im going get the alternator checked again if it happens tomorrow. I'm kind of stummped wanted to see if anyone has had the same problem or any other ideas on what it might be. Sorry for such a longgg post. thx for the replies.

MDTAHOE

Replace the alternator. The stores do not all ways have the best tester.

ericnottelin

Ditto to MDTahoe. There are a lot of electronics in todays alternators and the majority of the personnel at the local auto part stores don't know how to properly test them. Sounds like the diode in the alternator is intermittently failing. That would definitely cause that problem you are seeing.

Worst case scenario, if replacing the alternator doesn't fix your problem, bring it back.

Hope this helps

Eric

hfdff

Thanks for the replies. Well it happened again this morning and instead of driving it I took another vehicle to drop the kids off. I took off the alternator and took it to a different auto store and ahad them check it out and it failed. Put the new one on, no battery light and volt gauge read 14 volts, and reading 14 volts at the battery. I probably didn't need a battery and should of just went with my first thought about the alternator. Live and learn. I hope this helps someone else. Thanks again for the replies.

Thumper_ehhhhh

Glad it worked out for you. If your battery had a bad cell it needed to be changed anyway. I just did both on my burb not to long ago also.

gfd749

just for info for anyone else who may have the problem. the problem sounded like it was a bad voltage regulator on the alternator. on some alternators it can be changed and on some its internal and have to change the whole alternator. if u notice any gauges twitch as soon as u turn on your headlights or twitch each time your turn signal is lighting up then it may be your voltage regulator.

ericnottelin

Glad it work out.

Eric

Trisha Smith

Hey, same issue here... kinda.
on the long weekend, my truck sat from Thursday til Sunday, nothing new, but battery low, wouldn't start. got a boost, it ran great. Bout a week later, got up one morning, same thing. Tried the trickle charger.. too slow, got a boost... just fine, same thing 2 more days in a row.
Don't think it is alternator, otherwise it would just stop running, right?
Think it is just the battery.

tech2

yep.

the battery must be ruled out before any starting or charging system diagnosis anyways. get your battery tested

toddgruenhagen

Hi,

Jumper cables mis-applied. Reversed the positive and negative on the good battery. Alternator started to smoke. I assume the alternator is fried. What other electrical damage is likely on a 2000 Silverado?

Thanks