Help with alternator !

[mp1472]

Hello so i bought a 1985 Blazer and the po has done all kinds of work to the truck so ive been slowly trying to make sense of it all ... so anyway it looks like he added a 3 wire alternator (see pic ) and it sounds like its about to die. It looks like a typical chevy truck alt correct for the year.

I was going to get a h.o. alternator anyway but i wanted to make sure i dont order the wrong one .. this is what i had in mind to replace it http://www.db-starter-alternator.co...IES HIGH AMP OUTPUT ALTERNATOR 87-93 7861-11

I cant get a good enough look at the case to see if the mounting holes look the same .. so anyway i think this is the right one can anyone confirm?

 

[lectric80]

The case can be clocked, so even if the holes don't line up when it arrives, you just pull the four bolts on the case and rotate the case halves. I wouldn't personally recommend that one, unless you keep your pulley, underdrive pulleys can severely reduce the life of the alternator. I would say find one for a Transport, 140 amps and a pretty easy bolt in, if you know what you are doing. There are a lot of good options for getting higher amp alternators, without spending the coin on a 200 amp that may not last very long.

 

[mp1472]

hum id for sure want it to last .. i need the hi amps because i always run a large system in any car i own .. that is why id like an extremely ho alternator.

 

[lectric80]

In that truck a 140 amp alternator is going to put out enough juice for most systems. If you are really worried about the amperage, get a second battery and isolate it to the system. Since the 140's are available as a GM factory setup, they are going to last longer than the higher amp systems. Most of the 200+ amp alternators in ambulances and police applications don't last more than a year in your typical vehicle.

*Disclaimer- All the information I have listed comes from a reputed electrical shop, who happens to be a friend. He didn't give the information to make more money, only to save others money.*

 

[mp1472]

humm good info to know i run 3 optima yellow tops in my current dd with a 50 farad cap . do you have a link to a 140 amper you would recommend?

 

[lectric80]

Here is a link to the Pontiac Transport alternator that is nearly a direct bolt in replacement, and provides 140 amps. This is one of the members here who added it:

http://coloradok5.com/forums/showthread.php?t=150135&highlight=140+amp+alternator+transport

Also remember that the rating on the alternator from the factory is 80% of peak. When my buddy would test, they would easily put out 160+ amps, but they are rated lower. Nothing in the alternator prevents hitting the peak output, manufacturers rate them lower for safety.