No fans run when the AC is on, the AC cools great when the car is moving. Both fans do turn on when the green wire is grounded. When jumpering connectors on coolant temp switch the one at the back of the motor will turn both on but when jumpering the one on the front of the motor neither fan turns on . I've tried checking both switches, they both will only go down to about 750k ohms when in water over 200*. It looks like the two switches are bad and maybe the fan control module, but I'm not sure. can anyone else confirm this?

 

I think that the temp sensor on the thermostat housing (temperature sensor A) should close right at 200F. The front one (temp sensor B) closes at 223F and will only enable the fans when the car is turned off. If you have a continuity function (open or closed circuit), you can try that on the temperature sensors A and B. If A doesn't close at 200F (you can suspend it in boiling water at 212F), then replace. You may want to replace those anyway to ensure they are working properly.

The problem is that the green wire should still get grounded through the a/c diode. That is the only thing that can cause your problem, since the compressor still runs.

A diode will only allow current to flow in one direction, so a continuity test will read open using touching the positive lead on one end an the the negative lead on the end of the diode. It will read closed if you switch the volt meter leads on to opposite ends of the diode.

 

That sounds like a good analysis, I know about foward and reverse biasing of diodes, but where would the AC diode be located on this vehicle? Plus you mention an open and closed circuit for those switches, checking continuity on a meter should do the same thing, right? my question for that is for them to be good should they read open when cold, and closed (zero ohms) when above the specific temperatures? Mine seem to read in the K ohms when in hot water. (like 75-200KOhms)

 

I finally located where the AC diode is located, but quess what, there is no diode in the connector. Its the a small square connector coming off the harness above the driver side fuse panel. It has a green and red/white wire going to it, but its empty. Does anyone have a part number of this diode, no one, even the Honda dealer cant come up with one. This certainly has become a real patience tester.

 

I am glad you figured out the problem.

On the OEM parts website hondapartsnow dot com, there is an entry for a connector, diode. The parts blowup shows it on the passenger side of the car. It may be the socket for some other diode. It is under the electrical.., then wire harness.

15 32146-SH3-003 CONNECTOR, DIODE (2P) USA 1 $11.50 $8.34

I will take a look at mine to see if I can find a part number.

 

I inserted a 1N4004 diode into the socket and everything seems to be working fine, both fans cycle on and off with the ac on and car idling. One thing that still appears to be wrong though, but I'm not sure how critical it is, when I put a jumper across the ECT switch B (condensor fan engine cooling switch) both fans dont come on, at ECT A both fans will come on. Not sure why that is, but what is the purpose of this switch because the fans will turn on at about 205* from the ECT A switch, switch B suppose to turn on at 220*, by then the fans are already on.

 

No, fan switch A (thermostat housing) is responsible for switching the fans when the engine is running. Fan switch B is responsible after turning off the engine. You'll probably notice that shorting fan switch B when the engine is running (but not even warmed up) is not supposed to make the fans run.

The fan control module is supposed to control which fan switch has authority at the moment. Try shorting fan switch A when the key's turned off - the fans aren't supposed to do anything.