I have a 96 LX Sedan with 187K and 5spd tranny. Recently it has begun overheating when sitting still and I have determined that the fan motor is not coming on. It has had quite a work out in 100 degree heat this summer and a 150 mile round trip commute 5 days a week.

My question is this:

How can I determine if the problem is the relay, the fan motor, or something else entirely?

I hate to start throwing parts at it without a reasonable idea of what it could be. I can probably get a good relay to test mine but how do I go about testing the motor? Can I use some sort of motor tester? Thanks!

 

Jumper wires directly to the battery will tell you if the motor works.

Then you can check the rest of the circuit like this...
Follow the LOWER radiator hose back towards the firewall, to the thermostat housing. There's a fan switch back there, with a plastic plug with 2 wires. Unplug that & jumper between the wires with a paperclip or something. Key ON, that should make the fan run. If that works, then you've just verified the entire circuit including relays & timer-module. In that case, replace the fan switch that's screwed into the T-stat housing.

 

So to test the motor itself I just attach jumpers directly to the fan wiring? Is that right? Thanks!

 

Does the a/c work in your car? If so, turn on the a/c when the car is running, both fans should turn on. Let us know what you find.

If one of the fans is not running, I would unplug the electrical connector to that fan. Grab a volt meter. Start the car and turn on the a/c. See if you have 12V across the pins that go to the fan motor. If you have 12V and fan is not working, replace the fan. If you don't have 12V, then you will have to troubleshoot the relay next.

 

4 cyl or v6 i assume it is a 4 cyl.............Like PA said BOTH fans come on so which fan is not working ,,different troubleshooting if it is only 1 fan or both fans inop ,,,,,,first chk the fuse box under the hood, if fuses is ok,, do as Jim and PA advised

 

Okay, here is what I found out.

First off, I do have the 4cyl, sorry for the oversight.

Only the radiator fan is non-working. AC fan seems to be working fine. I have bypassed (with a paper clip) the the coolant temperature sensor and the fans comes on although it did so with the relay removed.

Is there a way to test the relay itself and find out if it works? (Since the fan worked without it even installed I can't imagine any other bypass that would tell me anything. )

Thanks!

 

Just to make sure that we are talking about the same fans.

Passenger side fan = radiator fan. Drivers side fan = a/c condenser fan.

The radiator fan relay is in the engine bay fuse box. The condenser fan relay is bolted to the condenser fan shroud.

The temp sensor that you shorted hopefully has a green plug and was on the thermostat housing?

Which fan(s) turned on when you shorted that temp sensor connector? Which relay did you remove?

 

Okay, I'm an idiot... or at the very least that's what I get for checking stuff in the heat on an empty stomach and low blood sugar.

The fan that was coming on is indeed the AC fan. The Radiator fan did absolutely nothing when I shorted the temp sensor (which I indeed did the correct item on this one!). The relay is the radiator fan one under the hood.

I am ASSUMING that if it was the temp sensor that both fans would come on when I short the temp sensor.

Therefore, I am assuming that it is the fan motor or the relay.

I am planning on checking the fan motor with an Amp Ohm Meter and either replacing or else replacing the relay.

Is there any flawed logic here? Thanks!

 

Make sure the radiator fan relay is plugged back in.

Unplug the electrical connector going to the radiator fan motor. Start the car and turn on the a/c. Measure the voltage across the two wires that lead to the fan.

If you have 12V, the motor is bad.

If you don't have 12V, swap the radiator fan relay with the power window relay. See if you get 12V (and check if your power windows don't work).

 

Where is the Power Window relay located? Is it in the interior? Thanks!