My son just obtained a 96 accord LX, it appears that for sure the condenser fan does not operate and maybe both as we have yet to see either one come on. The A/C cools fine when the car is moving but either fan comes on when the A/C is on. I checked for voltage at condenser fan plug with A/C running - no voltage. Checked both fuses (cooling fan) and (condenser fan) and both are fine. Now I swopped the A/C relay with the power windows relay ( as they are the same) and no change, windows still work fan doesn't. Now here is where I'm confused, I checked the A/C relay voltage and it reads a constant 12 volts with AC switch on or off, so I then checked the power window relay power and it goes from 0 to 12v when opening and closing the power windows. What do I check for the cause of the AC relay voltage is constant, and why does it not close the relay if there is voltage on it? Thanks for all your help, I've read thru all the past posts on these fan issues but couldn't find anything on this problem. RN

 

There is a possibility the ecm is not telling the fans to come on.
Or there may be a faulty fan switch thats not sending the signal to come on.
Also,be sure the system is fully charged too.

I had a car once that when you turned on the A/C,the fan would not come on...it would not cool but when you drove it,the airflow cooled off the condensor....and it began to cool off inside the car....it turned out the ecm was bad,and a new computer allowed the fan to come on as required.

 

Lets get some terminology straight.

The radiator fan is on the passenger side and the condenser is on the driver's side. Each fan has a different relay. The radiator fan relay is in the engine bay fuse box, while the condenser fan relay is bolted on the condenser fan metal housing.

The ECU can supply ground to turn on the relays. Also, the coolant temp. sensor can also supply a ground path for the radiator fan relay. The condenser fan relay can use a ground path through the a/c diode.

For starters, unplug the radiator fan relay and test for 12V on the pins coming from the fuse box. Make sure the key is in the II position when you do this. Use the red volt meter lead on the pin and put the black lead of your volt meter on a good ground (like a bolt on the valve cover).

Two of the pins (pins 3 and 4) should have 12V with the key in the II position. One pin should have continuity to the blu/blk wire going to the radiator fan (pin 1). Pin 2 is grounded by either the ECU or the engine coolant temperature sensor A to turn on the relay and power to the radiator fan. If you jump the two pins on the green plastic connector going to coolant temp. sensor A (located on the thermostat housing) then turn the key to the II position, the radiator fan should turn on.

Do similar tests for the condenser relay. The condenser fan relay and the a/c compressor relay are right next to each other. To identify the compressor fan relay, the wire colors going to that relay are wht(pin 3); yel/wht(pin 4); blu/yel(pin 1); and grn(pin 2).

 

What you are calling the radiator fan relay is what I inadvertently called the AC relay, it is located in the fuse box under the hood, and it is actually called cooling fan on the fuse cover. This is where I measured 12v across the normally open side of the cooling fan relay with the key off, AC off, its always there. I cant understand how that is possible with no fan running. I have no manual or wiring diagram so it makes it hard to find what your talking about, are the condenser fan relay and the a/c compressor relay mounted off a bracket coming off the top bolt of the fan housing? they are black rectangular devices with no wires on top but appear to have wires off the bottom? Do the haynes manuals show these devices more clearly. I apoligize for the clarity of what I'm asking, its just hard to describe things that you dont have the true nomiclatures of. Thanks again for taking the time to answer.

 

I was just trying to make sure we were consistent on what to call the components to avoid confusion.

The pins on the radiator fan relay will always have power, because the relay can be turned on when the car is turned off via the Coolant Temp Sensor B.

Those two black boxes you described are the condenser fan relay and the a/c compressor relay.

What I was describing came from a 94 shop manual that you can download from the spooner link I posted on the online manuals thread in the DIY section. It gives a wiring diagram of the system. It is under heater and a/c section, a/c, then circuit diagram page 22-5. Page 22-4 shows the location of the relays.

 

I picked up the haynes manual and now have a good idea of where all the components are located. I followed thru some of their trouble shooting techniques and found this. They have you check the Fan Control Module that is behind the glove box, I checked for all the required voltages it stated and they were all present. Then it told me to jump the green wire to ground, with the ignition on and AC off, both fans do come on. Now what does that mean, they dont explain what it is if it does come on, just if they dont. Does that mean that the module is bad? This is killing me. Again thanks for all your help on this matter. Rick N

 

One more thing to add to the above, When jumpering the harness connectors at the ECT switch (for the radiator fan) both fans come on. But when jumpering the switch for the condensor fan (both located in the radiator cooling housings) neither fan comes on. I hope this will help someone figure out what my problem is. Thanks

 

http://techauto.awardspace.com/overheating.html

give this a shot..

 

Grounding the GRN wire should turn both the condenser and radiator fan on.

 

Since the both fans turned on, both fan motors and their relays are working. If the compressor engages, then the compressor clutch, relay, and the a/c switch in the car are working too. So you can eliminate those items.

On the black wire going to the radiator fan control module, does that wire have continuity (~ zero resistance) to ground?

Also, you never mentioned if either fan is running when the car is running with the a/c turned on.