Alternator Upgrade

[Oregontrav]

I have an 89 comanche and I'm considering and alt swap because of the power drain when i have the heater on and blinker probly just gonna putt the 100 amp in is there porblems with going up if not can i go to 140 or 200

[Eagle]

The '89 used a GM CS-130 alternator. Those came in two or three different physical case sizes. I found out the hard way when I had my alternator rebuilt for my '87. I wanted to upgrade from an 85-amp to a higher output, and the guy found that the higher output requires a larger case. I was committed at that point, so I went ahead. If I had it to do over, I would go to AutoZone and get one of their new-manufacture Gold alternators and have a lifetime warranty on it.

 

You should have no problem going from a 100-amp to a 120-amp. I don't think you can go higher than that due to space limitations.

 

Keep in mind that in 1989 the 100-amp was the high-output option. If yours can't handle the heater and the turn signals, either your alternator is failing or you have other electrical problems.

 

[omega_rugal]

i would check that alternator first...