So, my alternator crapped out on my wife last week. After getting it changed, the battery light was on. So I went and checked the battery, and it was reading 6v. So I pick up a replacement battery, and I thought the problem would be solved. The battery light is still on. It blinks intermittently, and it goes out for a time, only to return. Any ideas?

 

Check for loose connection or battery cables may have high resistance

 

Double check your connections on the alternator. Also was this a rebuilt alternator installed. Sometimes the replacement alternator could be faulty from the beginning. Happened to me just yesterday.

 

Double check all connections. Seems like something is wrong along that line causing it to flash...... alternators sometimes are faulty as well. I have a car dealership and thats one item that usually is bad 3/10 times form the beggining.

 

I also was told that the GS don't like aftermarket positive terminals. As mine has some kind Walmart type of terminal. I stopped at the Lexus dealer and picked up positive terminal. I am going to try that tomorrow. That alternator is a PITA to do.

 

I got rid of the aftermarket positive battery terminal and went to Lexus and got another one. I started the car, and the battery light was still on. Next I replaced the belt. Good results I think. When I started the car, the battery light went off. In fact it stayed off while I let the car run for about 20 minutes. So I am thinking everything is ok. So I go to the store, no battery light, everything great. When I come back out, the battery light comes on momentarily, then goes off. Then it comes on and stays on. for about five minutes of driving. Once I got on the freeway, and got up some speed, it went off, and stayed off on my way home. I am wondering if the alternator is actually working, and is charging the battery again.

 

Have the new alternator tested just to be sure. But what you're describing may also be a belt tensioner issue. if the spring inside the tensioner is getting weak then the belt could start slipping on the alternator pulley.

 

I puled the alternator back off. I noticed that the alternator plug has some burns on the end of the plug. Is this common? I am thinking I need to replace the plug. Lexus don't sell it. Is there anyplace I can get one? I am wondering if this can be my problem?