94 battery problems

[mlcase27]

I have a 94 and lately when my lights are on (low or high) beam my lights dim when I brake, it also happens when I turn my heat on. Can this be the battery going bad? Its almost 3 years old. I had the alternater checked and it is good. Any help? Thanks.

 

[BrianDye]

It could be your battery, alternator, or wiring.

Have your battery checked, if it also tests good, you may want to upgrade the "Big 3"

Thats basically getting some 0/4/8 (Your choice, but thicker, better than stock) gauge wire and replacing the wiring from 1. Your alt. to battery 2. Body ground 3. (Cant remember the 3rd off the top of my head, maybe battery to chassis?) Do a search for "Big 3" or "Big three" and you'll find plenty of info about it.