What size relay?

Just picked up an electric fan at U auto pullit and was wondering if anyone knows what size relay will suffice to run the power through. Also, who would carry something like that. I'll need the relay and the base. Thanks in advance.

 

Amazon has several listings for automotive relays and sockets.
Here's one: http://www.amazon.com/Fastronix-Rel...6?s=automotive&ie=UTF8&qid=1306520518&sr=1-16

 

You need to make a guess at how many amps the fan pulls at peak. Compare it to similar sized aftermarket fans. Note their amp rating, and double that. That's your minimum current rating for the relay.

Some of the car fans pull a heck of a lot of amps, as I recall. Here's an article on Pirate that recommends a 100 amp relay: http://www.pirate4x4.com/tech/taurus/index.html There's also some discussion in the Pirate forum threads which you can find if you search.

The only reason not to go big here is cost - functionally, bigger is better and more reliable.

 

Will and electric fan pull more that the headlights?
A relay that handles headlight hibeams should work nicely.
And they should be available at the local FLAPS.

 

Substantially more than headlights. IIRC a headlight is around 35 watts or about 3 amps each. Not much at all compared to an electric fan.

 

I wired in a 40 amp relay that I had laying around from some old off road lights. Seems to be big enough. I put a 30 amp fuse in line to protect it. We'll see how it does.

 

My headlights are more than 35 watt and there are two of them. Even at 35 watts times 2 that would be 70watts.
My Jeep utilizes 50/55 watt or 55/60 watt sealed beams. Came with the 50/55 watters, but they sometimes can be hard to find since the 55/60 watters are more prevalent now.