I'm considering getting new fans for my new engine. I have a thread started in the cooling section. However, I have a question about the electrical side of it. The two fans are rated as 2500cfm @ 20 amps and 4000 cfm @ 50 amps. I'm assuming my alternator (stock replacement for LG4) can handle the 20 amp fans. But the 50 amp fans I'm not so sure about. What would you upgrade/replace if anything to handle a 50 amp draw like that? Is a 50 amps too much?

Thanks.

 

Yes, 50A is too much. Our engines do not need that much cooling.
If I'm not mistaken, the stock fans are rated at 10A continuous, 20A startup, each. No idea on air flow specification, though.
If you go above 20A, you'd need to make sure that the wires can handle it (the relays sure can) and of course the main fuse would need to be upgraded (it's right by the battery, on the fender).

Hope this helps.
Lou

 

Lou,

Thanks, that helped. I'm looking at different fans now, hahaha, I can't make up my mind. They are made by Spal, and the ratings say:

Test Voltage: 13 vdc
Current input: 25 A
Airflow: 2780cfm

I think these would do better in my application. Do you think the current is more reasonable? Upgrade the main fuse still, I would imagine. To what? 25A? 30A?
Thanks for your help.

 

25A seems like a lot of current for 2780cfm. On my truck, I use two 10A fans (total 20A) that give me 5800cfm.

Is their current rating meant for start-up current?

Yes, you could just upgrade the fuse to 30A and it should work no problem.

Lou

 

The Spal fans seem to be working for other people, and they fit in my price range. I'm not sure how they do their CFM rating, so maybe lets ignore that for right now.
The specs I was able to pull off their website doesn't say if it is start up current.

With the upgraded fuse and probably a larger current draw then the stock fan should I be concerned about my alternator? Its just a stock replacement for an LG4.

Thanks

 

Alright, I'm bringing this one back...

I purchased the Spal dual fans. Which work great btw. They have 2 relays with two 30 amp fuses. They are wired up and working fine, kick on, kick off, no problems, kinda.

When the fans kick on, they seem to like a lot of juice. The battery gauge reads fine, but man it really slows the idle down on the engine. The biggest draws on the system are the fans and the ignition system. I'm thinking the alternator is giving all its got to feed these things? I'm not sure. Could use some help. Thanks..