Charging System Blues ?????? (New Battery & ALT)

[BigBlackBurban]

Greetings, One of my boys just purchased a 96' Suburban. (I am trying to get him to join this forum, but that is the least of his problems). He told me that he came out to start the truck Sunday morning and it was dead. He had the alternator checked and it was bad (so auto zone said). He had the alternator changed, it drove fine and started all day. The next morning the same thing dead. He then changes the battery (pep boys claim dead cell), drove and started fine all day the next morning, you guessed it dead. I have no idea what he should check next. BTW when he jumps it, it will start right up and run all day until parked over night. I asked him to check all the interior lights and he claims they are all off. He has no alarm or aftermarket sound system in the truck. What do you guys think?

 

[95TwinTT]

You need to get a current meter between the battery and either the pos or neg connector. Which ever one is easier to get at. Try unplugging fuses until the load goes away. If that does not isolate it, try pulling relays in the "under the hood" control box.

There has to be something that is taking it down. Don't throw anymore parts at it until you isolate where the problem is.

I'm assuming you don't see any lights on when parked? There could be a relay hung up somewhere. Good luck........

If you don't have a meter, you can get a fairly decent one at Radio Shack, for $40.00. :yesnod:

 

[YukonMud]

Sorry to hear about your electrical issues.

In my old truck I had some electrical issues as well. It was not so much of a draining issue but more of a short somewhere. If I were to turn on my lights, wipers or both the voltage would drop a little and haven forbid if I ever turned on my blinker too. If all were running my volts would hold steady around 12 and when the blinker went on it would drop to 9 or 10. I spent too much money trouble shooting and eventually ended up getting a high output alternator & optima red top battery, which did a good job of stabilizing everything but it did not truly fix anything.

 

[loulblades]

I have also discovered that a battery going bad can take an alternator with it due to the lack of current reg on these alts. I went through several alternators and batteries before getting it right.

A note: I will never buy a Wally world battery again, even though I know many batteries come from the same source.

 

[BigBlackBurban]

Thanks for the replies, I'll pass the info on to him and go from there. Update to follow.

 

[sasquatch094]

im not sure how much that light under the hood really puts out, do you think its a possibility that that under the hood light is burned out and its still drawing juice??? my capri does that until i took the stupid bulb out.. idk if that would be an option or not??? beats me.. jsut a wild guess..

 

[GMCYukalade]

take the batt cables off, and cleam them really good.. make sure they aren't corroded at all.. and then make sure they are really good and tight.. - i mean.. its an idea? if they are kinda loose.. and during the morning.. they may not connect properly... than u put charger on..? and it tightens em a lil.. i dunno