My 2zz swapped mr2 randomly dims power to the lights radio everything as I drive. Then if the battery is under 12.4v the lights will not work and it will not start.charge it to 12.7 no problems again. The battery tests as good. The alternate tests as good. But sometimes when I check the battery when it is running I see 12.5v and slowly dropping. .other times it shows 14v when running. No idea. Just cleaned every ground in the engine bay and yes battery terminals and wires. Although they were really clean. Any ideas of some relay or control module that might be acting up? I think maybe the alternator is possibly intermittently acting up. I took it out to test it... but that was so much fun that I think I will just replace it anyway. Not much room in there.