yesterday I noticed the car temp start to go up while driving. fluid levels are good. when I cranked up the cabin heat the temp went back down. just tested the fan (the one on the passenger side) with direct 12v and it works, then I jumped the pigtail to the fan switch, turned the car to key on and nothing, turned it back off and THEN it runs. Weird. Is that the right test?

 

Please tell us what vehicle you are driving. My signature has this information, so I never have to remember to post it.

 

Ok it was in my signature, not sure what happened there. 93 Accord 5-Speed.
My timing was way off, that seemed to be the problem but I'm still not seeing any fans spin while it's running, only the passenger side fan spins for 5 min after i shut it off usually.

 

I don't think the car would overheat with the timing being off. What did you do to fix the timing? Also, why was it off?

There are two temperature switches in your car. Temperature switch A is on the thermostat housing and has a blue and black wire going to it. I am pretty sure the connector is green too. Is that the connector you jumped?

 

I rotated the distributor until it ran better. Timing was off because I just had a new cyl head and timing belt kit put on, had a shop finish what I started and the mechanic "left distributor where it was" assuming I wanted to do the timing but I've never done that before. For all I know it's still 180 off but I got it to drive smoothly rotated almost all the way the other direction, clockwise. Didn't think that would effect the temp either but can't get it to overheat now.

Yes that's the plug I jumped. It made the fan run when the car was off but not when it was on.

 

The locations of the two temperature sensors is different on the 4th gen accord vs my old 5th generation.

On the 93, the thermostat housing is on the upper radiator hose and should have temp switch A. I think temp switch B is on the housing for the lower radiator hose.

The connectors are the same and they are green plastic. Verify the wire colors going to each sensor. Temp sensor A on the upper radiator hose should have a black and a blue wire. Temp sensor B should have a black and a white with green stripe.

Verify the wire colors. Just want to make sure the connectors didn't get switched during the installation.

 

PA, the 4th and 5th gens are the same.......me and my old 3rd gen's are different.

OP- on a 4th gen (90-93) the upper hose connects to the head at the front of the engine - between the head and the rad....that is where thermo B is. Thermo B only controls the one fan when the car is off - key off.

The lower hose connects to the engine behind the head - head to firewall. That is where the t-stat is an also where thermo A is. Thermo A controls BOTH fans when the key is on.

 

To add test BOTH fans with direct power and ground just to rule them out.

Then re-test using the fans switch on the lower hose with the key on - BOTH fans should run.

 

Ok thanks guys. Yeah still overheating at times. The switch near the housing on top is getting the white/green-stripe and black wires. Yes A and B take the same plug but it looks like they are right as the one for A (the one I'm pointing to in the pic) doesn't reach B.

Both fans run when I give each one 12v directly. Passenger side fan runs when I jump B and turn key off. Neither fan run when I jump A with key on or off.

 

Testing the wiring is a bit tricky for the fan setup.

You can unplug the radiator fan control module that is located under the glove box. It is a small black plastic box with around 7 wires going to it. Short that connector at temp switch A and see if passenger side fan turns on.