View Single Post
Old 08-15-2020, 12:00 AM   #31
Registered User
dmjlambert's Avatar
Join Date: Apr 2016
Location: Cypress, TX
Posts: 2,076
Re: Stock alternator to 12 SI alternator

Originally Posted by tdangle View Post
I'm looking at a 100 amp alternator. If I read the charts I've found correctly, I should probably have a 6-8 gauge wire off of the alternator
The question is, where does that wire run to? If you have a load that will be drawing a bunch of current, you can run it to that load. If you expect the battery to supply a bunch of current to a device when the alternator is not running, then I suppose the wire from the battery to the alternator and that device also needs to be fat.

I don't have any big loads to worry about although I have a big modern alternator, so I didn't do anything to the stock wiring. I suppose it will be a good idea for me to add a fusible link at the alternator to reduce the risk of the alternator cooking my 12 gauge wiring if I have a short.

If I were to add something that hogs a lot of electric current, I think I would power it from the alternator with a fat wire and use a relay to only connect that device when the alternator was running. The CS144 alternator I have supposedly has a tach output that I would send to a driver/computer for a relay. I can't think of any big current draw that I want to add. Electric fan doesn't make much sense since the engine is right there and works with a mechanical fan far better than converting rotational power from the engine to electricity and then converting that electricity back into rotating a fan. That would be very inefficient to do that energy conversion twice. Electric fans are for front wheel drive cars when the engine sits in the engine compartment sideways. Just my rambling opinion.
dmjlambert is offline   Reply With Quote