Need alternator

[turboman93]

Hey all,

Forgive the newbie question, but I have a 94 C1500 Suburban that needs a new alternator. I've been looking and there's like 4 different ones for that year ie 100A, 105A, 120A, and 124A. What is the easiest way to determine which one I need? I have the 5.7L gas engine in the truck.

TIA!

 

[c1500deathtrap]

Bring the old one to a parts store and match it up? Or maybe look for an old PN on the bad alternator.

 

[turboman93]

OK, I was trying to find out what I needed without taking the truck down. Thanks for the response.

 

[DerekTheGreat]

Check the RPO codes on the sticker in the glove box if you don't want to remove it. Those are one of the cool things about GM vehicles. My truck decoded as having a 100 Amp alternator. For 1989, I think that was optional. I have a breakdown of all of my RPO codes at home but forget which one pertains the alternator, although if yours is base it might not be on the RPO sticker at all.

 

[Hightower1]

Anytime I have replaced an alternator on any of my vehicles I always go for one with a higher amperage than original. If you run any aftermarket accessories like fog lights, stereo/amps, high performance ignitions or anything else it just gives the vehicle a lot more amperage to feed off of and makes everything work better. More than likely the alternators you are looking at will all fit your truck, I would personally go for the 120 or 124.

 

[DerekTheGreat]

Not a bad idea, so long as the charge cable can handle the amperage.. If GM was smart they would have used a charge wire rated for the highest output alternator for all of the trucks regardless of which alternator it actually had. Not sure if GM was smart though.

I upgraded the alternator on my Town Car and had to step up the wire gauge to support it. The stock 60Amp wasn't cutting it.