Lately when i drive the 4runner i get this weird problem. It runs great throughout but the volt meter will drop from around 15v to 12v and the 3 dummy lights will come on. The at temp light, parking brake light and battery light. Then after 20 seconds they all go out and the voltage jumps back up?

Any ideas. I'm thinking my alternator is on it's way out since it's the original 91 alternator.

91 4runner sr5
auto 22re
235/75/15 BFG Land Terrains
154,899 kms and still like new!

 

Could be time to rebuild the alt. I would check that first.

 

Your alternator is dying a painful death. I just had to replace mine and my cluster was doing the same thing.

Rob

 

Be sure and load test the battery while yer at it.

MIke in AR