Hi I have just installled an electric fans on my 1994 f-150 2wd 5.0l truck they work great I bought a 16 in and a 12 inch fan off ebay and I bought a thermostat kit from autozone.

I then used a relay I have a 30 amp inline fuse from truck battery to the relay then I have one side go to the ground, then another to the thermostate and the last one is a swithced power source or also known as a ignition source so the fans only come on when the truck starts. ok so now one from the relay gos to the thermostate like i said and then the postive and negative of the fan go to the last spot on the thermostate and of cource the probe is in the radiator.

Yes very confuzing without a pic I will post one!

OK HERE IS THE PROBLEM! the swithced/Ignition source is pluged into the battery beacuse I cannot find a fuse or and place to splice into so I have the fans set to about 200F so the fan only stays on for about 1 minute when the truck is off. this sucks some people have used a fuse some spliced into the alternator wires I think they said the yellow black? one but I dont want to blow anything in my truck so what wire is a good switched power source? for a 94 f-150

please I just need info on the switched power source my fans work great no matter how crazy the wire setup sounds been doing this for 2 monthes and i drove it in 115F weather and didnt have a problem just really want the fans to go off when I turn the truck off and pic would be nice to. thanks!

 

This shows how to add a fuse:



The best circuit to tap is the FP relay output (DG/Y) in the underhood fuse block.

 

Ok I will try this tonight! Thank you.

 

Alright just wanted to give feed back, I didnt use that fuse I spliced into the alternator wire the LIGHT GREEN WITH RED STRIPE. It works very well, shuts off when the truck is off and comes on when needed. but the battery indicator is on in the dash? but the voltage readings on the dash are fine its probubly the ECU noticeing something diffrent but like I said everything work very well. I will post pics in a week or so!

 

That's not a good wire to tap for anything, and the ALT light is just one symptom. I'd restore that circuit ASAP & wire into a fuse correctly.

 

so even if its only being used as a switched soure its bad i didnt use it as my power source

 

Just wanted to give a heads up, I fixed that wire that went into the alternator. I put the ignition source wire through the firewall. then found a turn key fuse in the cabin the lower left fuse box. it was a red 10 amp fuse I believe number 18 fuse. went to autozone and bought the double fuse slice in wire setup? I think that was the name. everything works great it not puting up any warning on the dash truck runs way better!