How to Check Your Cars Electric Fan Motor

When your car or truck overheats you should always check and see if your fan is running. In late model cars we have gotten away from the old belt driven clutch fan and gone electric. This is to improve power and performance and is really a good thing, most rebuilders are retrofitting with electric fans also these days.

Difficulty: Moderate

Instructions

Things You'll Need:

• small piece of 16-20ga wire
• test light
• patience to trace wiring system(this one is hard sometimes)

1. 
    
   fuse/relay panel

   Ok, the first thing we want to do is see if the electric fan motor is running when the ac is in the on position. If it is the fan is not bad it is probably in the coolant sensor, relay, or computer system...

2. 
    
   test light

   If the fan does not run with ac on then open relay/fuse panel and check fuse first. It should be marked which slot it is in. you will simply groung the clip end of your test light and with ac/car running probe both sides of fuse. If you lite up then the fuse is good, if not replace the fuse.

3. 
    
   relay

   If you have power at the fuse we need to check the relay. I always use a small wire as a jumper across relay terminals 85 and 30 on most vehicles. Your electric cooling fan relay location should also be marked on fuse panel cover. If you jump across these terminals and fan comes on then relay is bad.

4. If you cannot make fan come on at this point then find your wire connector to electric fan. It will have either 2 or 3 wires in it, you will want to find the hot wire and with your test light clamped to the positive side of battery, probe hot wire like you were using the jumper and see if it runs then. If not you will need to replace the fan motor.

Tips & Warnings

• I usually replace the coolant sensor at the same time as a precautionary measure...
• Be sure and jump your hot wire or you could blow a fuse...

[mralarcon]

on 11/7/2009 How to Make Money On Ehow
Good info thanks

[chrisanimelo444]

on 8/5/2009 Interesting. This is good to know! Thanks. :)