Hello, i have a 2002 cadillac escalade ext, i use it for weeks at times but sometimes it just sits there for 3 or 4 weeks straight. Anyway i baby it like nobodies business! Everything is done when its suppose to and recently i was driving it and when i press the break, the battery gauge goes down and all the lights in the dashboard and headlights go down like if its losing power. I recently took the battery to get checked and its ok. Its a optima battery. So im pretty stomped on what can be the problem. Can anybody please help me out on this?
10-28-10, 03:05 PM
I would say that a good way to test it is by disconnecting the battery. Cars use the battery to start it then it runs off of the alternator. So I would think that if you started it then disconnected the battery and then braked and if it still did it I would guess that it is the alternator is going bad and it isn't outputting enough amperage to power everything. If it still did it with the battery disconnected then I would hook the battery back up and bring it into a parts store and the should be able to test it with it still on the vehicle. They will tell you what amperage it is suppose to produce and how much it is actually doing. Hope this helps but thats where I would start
10-28-10, 03:37 PM
I notice that while backing up at night my taillights will light up bright but as soon as i let off the gas they get lower... my battery gauge also does this.. if i hit the gas it will jump up but if i let off it get lower adn the lights dim out.. i talked to a few people and they all say its probably the alternator.. i am actually looking into getting a new one or maybe just upgrade to a high output.. but its probably just the alternator...
Yeah, that sounds like the alternator. When you press the gas, it speeds up the revolutions of the serpentine belt around the alternator, thus increasing the charging voltage of the alternator. If it starts to go, then it isn't going to provide as much of a charge as it's supposed to.
You really wouldn't need a high output alternator unless you plan on adding electronics. A functional alternator would provide more than enough of the amperage you'd need without any extras.