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GMC Safari alternator not working

gohammergo's Avatar

Join Date: Nov 2002
Posts: 127

05-17-05, 06:22 PM   #1  
GMC Safari alternator not working

Vehicle: 1991 Gmc Safari 4 WD, 4.3 V-6, Auto trans, electric windows, etc., digital dash.

Problem: Just bought this vehicle. The previous owner said it needed an alternator. The battery icon on the alternator gauge was flashing. I put a known good alternator on it, and the battery icon still flashes, but the light bars at the bottom of the gauge do move up to around 14 volts or so. If the light bars move up when you rev up the engine, does it mean that the system is charging? The lights are bright when running, everything electric seems to be fine. The guy we got this from said that the battery would drain down overnight, and that someone told him that if the alternator was bad that it could cause the battery to drain down.

What else could be wrong here if the problem is not the alternator ?

Thanks in advance for any help.

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cuedude's Avatar

Join Date: Jan 2005
Posts: 348

05-17-05, 07:04 PM   #2  
Hi Gohammergo,

I'm not a mechanic by any stretch of the word, but I have a few ideas. From what you are describing, and what I'm understanding is that the Alternator is suspect. After it was replaced, the light is still lit. I would first make sure there isn't a short somewhere such as the starter, or if it has one, the solonoid. And you might have the light circuit checked as well. Another possibility is the ignition switch. (Not where you put the key, but it's an actual electric switch, and one lead is a high amp hot lead). I realize that there are many more things that could cause this, but this will hopefully get you going toward a solution. I'll watch this thread and all the replies, and see where this leads.


carguyinva's Avatar

Join Date: Nov 2003
Posts: 1,147

05-18-05, 05:21 AM   #3  
read this...

...perhaps it will help you sort out what's what here...


jeff67's Avatar

Join Date: Dec 2001
Posts: 616

05-18-05, 02:33 PM   #4  
Get the battery tested at your local auto parts store. It might be failing to take a charge. It sounds like the alternator is working fine.

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