Darkalley

Hey guys so my mechanic will be installing my newly built 350 in about two weeks and I will be adding an electric fan. Should I also install a higher amp alternator? I am adding a retro sound radio as well. I’m not worried about being “stock” as nothing about my car is. What do the experts recommend?

Olds64

I added the Remy 20212 108 amp alternator to my 71 98 after a Jegs alternator I had for a few years died. It charges well and I also installed an aftermarket radio. I have plans to install an electric fan soon too.

https://www.rockauto.com/en/catalog/...generator,2412

Darkalley

I don’t need to swap anything else out of I add the higher amps right? My car is a 1970 Cutlass

cdrod

Electric fans can have a very high in-rush current when they turn on. Once they get moving, the current comes down and levels off. You can bench test the fans with an amp gauge to get an idea of the starting current and the steady-state current draw then bump your alternator capacity accordingly. Keep in mind that alternators are typically not rated at idle speed and can the current output at idle can be much lower than advertised. If you're not concerned about originality, you can swap in a CS130 alternator to get higher output capacity and better voltage regulation but you'll need to swap the connector that plugs into the alternator.

Rodney

Darkalley

Thanks! I just found this article after your post as well
https://www.hemmings.com/blog/articl...0-alternators/

matt69olds

This is the swap I made on my car years ago. The alternator will easily put out 90-plus amps at idle. Make sure you upgrade the charge wire, the added current will definitely let the smoke out of original charge wire. Anyone familiar with automotive electrical systems will tell you the smoke in the wires is what makes everything work. Let the smoke out, things don’t work anymore. 😎

stellar

cdrod

Stellar:
Love your jar of smoke!! Years ago, I worked in recoding studios and we used to call it "magic" smoke because nothing worked after the smoke escaped?

Darkalley:
matt69olds is correct about the charge wire. You should run a larger charge wire directly to the battery if you up the alternator capacity. I'm installing a 170Amp alternator on my car and will run a 4-gauge charge wire protected by a Midi fuse.

Olds64

To use high current draw electric fans you should use a relay to switch them on. I just tested a Ford Widstar fan this morning I got from the salvage yard and I used 14 gauge wire and the battery from my Olds. Of course you don't want 14 gauge wire when you install it. Here's a good kit to install an electric fan.


Make sure you don't waste money on an aftermarket electric fan. I spent $100 on a Jegs electric fan kit and it was a POS. The best electric fans are salvage yard finds from a mid 90s Ford Taurus and mid 90s Ford Windstar with the 3.8l v6, a late 90s Lincoln Mark VIII and the late 90s/early 2000s Ford Contour with the 2.5l.