Extra idler wheel for alternator to stop belt squeal

zukebob wrote: OlaGB. I apologize if it seems like I am using you as a test subject (unfortunately I really am to some degree) but wanted to see if you have had an opportunity to contact the alternator vendor. If they confirm that 145 amps is the rated capacity, I would really like to get some feedback if you have any buildup of heat with the alternator.

Thanks
Bob

Nope, sorry.. Asked them, but no response...

Ill try to get my hands on a DC amp meter and measure it while winching later, but ive got my hands full in so,e house refurbish project right now so itll have to wait alittle..

If i see 90+ amps, i`ll be ok with it. Sub 80 will make me consider going back to stock alternator, and get rid of the belt squeal again.

Thanks. If you ever have a chance to check the output, that is more than I hoped for when I first started looking.

Facade is correct about the specification. There are actually 2. The SAE spec that he mentioned and an ISO spec. Both specifications define the rated output as the output with the alternator at 6000 RPM. Idle output is defined differently with one spec being at 1500 RPM and the other at (an ambiguous) idle speed of the vehicle. The company that you bought yours from is in Hollywood, California. Any U.S. manufacturer or distributor is required by law to conform to the SAE spec if they list a rated capacity. It's not 100% clear to me what they are claiming in their advertisement.

Facade is also correct about the tag. The problem is that I doubt that yours is visible. If you can see it, the numbers listed are exactly as Facade says: Idle amp/Rated amp/Test Voltage

I knew I had seen a alternator upgrade thread that included idler work. Not exactly elegant but workable. As the poster mentioned, a larger diameter idler would allow additional belt contact at the alternator pulley.

150 Amp Alternator Upgrade

Ok, so i got my hands on a DC meter, and tested alittle yesterday.
Only tested at 2500rpm, but that should be sufficent?

It got to 85amps.. So a bit dissapointing for a 140 rated alternator, allthough i wasnt expecting it to pass 100A anyway.

Ive only got a cheap 45ah battery for now, and my measured voltage while doing a similar winch test on stock altenator, was down to 11.2-11.5, but with this new alternator it was never under 12.5, mostly above 13v.
Handbrake at max, 4x4 engaged, so it did pull hard. 8000lbs winch.

I havent tested the stock alternator with a amp meter, and have no idea if that actually gives the rated 70a.
But theres definently a big improvement in voltage drop.

I don't know the pulley ratios of the jimny but I would assume that 2500 engine RPM would put it a little over the 6000 alternator RPM that the rating is supposed to be based on. 85 amps does seem a little low but it sounds like it is better than stock. Still a good price if you are seeing improvement.

Thanks for taking the time to post the info.