Dual alternators question
 

ive got a 94 s10 blazer that i have running dual electric fans. when turned on my lights dim and so on. so i have all the items required to install a second alternator. i know i have to splice the excitor wire to the second alternator. but instead of running the output wire to a second battery i was wondering if i could just hook it up to my relay for my fans? would i burn up my alternator or relay?

Why dont you just do the big 3 upgrade?

X2 on the Big Three upgrade & instead of another alt. check out this ad in here...
https://blazerforum.com/forum/privat...rs-sale-72836/

No dimming lights with one of those puppies!!!
Are you sure the alternator & regulator in it are ok?

yes i know of the big three upgrade and so on... but i was wondering if the second alt would work the way i described?

Personally I wouldn't bother. All the mucking around & for what? A good high amp alternator like I posted from a MOD here, would suffice.

https://blazerforum.com/forum/privat...rs-sale-72836/

My dual 12" fans run fine, that's why I asked about the condition of your alternator. BTW

my alternator is fine. and thanks for your reply. but... i asked will putting in a second alternator in place of the ac compressor and running it directly to my fan relay and NOT a battery.. work?? will it burn up my relay?? will it burn up that alternator?? and to tell you the truth im not gonna buy a 300 dallar alternator to put in this blazer. ive actually been looking at my local pick a part for a ad244 high output alternator to replace mine for 20 bucks. but cant seem to find them. anyway could you tell me if that would work or not or will it burn something up.

Honestly I'm not sure, I can't see it being good for the fans getting an unregulated voltage/amperage into them. The battery acts as a buffer of sorts only allowing out a certain voltage & amperage.
I googled it & found an interesting reply to a guy that wanted to wire efans directly to the alternator...
"do not under any circumstances wire a thermo fan to the alternator unless you want to cook any voltage sensitive device. a fan will work just as happily as a generator when air flows over it but does not have the advantage of being regulated so you will feed random voltages into your wiring system. Manufacturers go to extreme lengths to stop this using zenner deiodes and more commonly relays with internal diodes."

He also talks about the fans (when not being powered) generating power back to the electrical system or in your case to the extra alternator.

Maybe call an alternator/starter shop & ask. If anyone should know it'll be them.

We understand where you are coming from, but honestly, even with the alt you have now. Doing the big 3 upgrade will be more than enough for dual e-fans. I mean, if a toyota camery can have dual e-fans, a blazer can with out a problem.
Big 3 and call it a day

I have done the big 3, and can run my AC on full blast, and crank my music (1000w amp and 12" sub) and have the headlights on, and there is no flicker in the lights, you have to REALLY look HARD to see any sort of slight dim in the dash cluster (which is also digital)
So I think adding an extra alt is just over board for some e-fans. but to each their own

but like rottidog said, running the alt directly to the efans will fry them faster than an egg.

I run dual 12" fans for the rad on mine with a stock alternator & no Big Three done to it.
I'm not sure why yours is having an issue.

That is what I am wondering. Before i did the big 3 on mine i was still running 500 watts and did not have a problem. There has to be a problem somewhere, alt, batt, ground issue.