95 Taurus AC and radiator fan not working

The radiator fan is not working and the AC only works intermittently. I have replaced the Constant Control Relay Module and the temperature sending unit and checked all fuses.

The fan is good, I've checked it. The plug to the fan has power when the car is first started for approximately 8-10 seconds then no power. If I turn the car off then restart it, again power for a short time then no power
The AC compressor kicks on and off. When I drive the car on the highway, the AC works fine until the temperature starts getting too high.

What else could this be? Frustrated, any help will be very appreciated.

The a/c compressor kicking on and off is normal, if the compressor ran non stop it would build way too much pressure and blow lines and/or fry the compressor. The reason it stops blowing cold air is because of the elevated engine temperature.
As far as the radiator fan goes, there are a number of things it could be. Fuses, relays, sensors, faulty wiring. You'll have to go through the entire circuit connected to the fan.

The radiator fan will only run when the A/C compressor clutch is engaged or when the engine coolant temperature is reported as being too high. As mentioned above, it is normal for the compressor to cycle, but if the cycling is too frequent, the refrigerant charge may be too low or too high. You need a manifold gauge set to monitor both the high and low pressures at the same time to properly determine if the charge is within the correct range.

Just to make sure we're all on the same page, when you state that the AC works fine until the temperature starts getting too high, are you referring to the cabin temperature or the engine temperature?

-Rod

Thank you for the thoughts. Yes, on the highway, the AC quits working when the engine temperature gets too high, or when I slow down to lower speeds/idling/etc. But then as the engine temp gets over half way, the AC stops working altogether. Prior to all these problems, the normal operating temperature was very low on the gauge.

I tried to charge the AC system, it is full and would not accept any more refrigerant. I really believe the radiator fan not working is the root of the problem. I just can't figure out why there's only power to the fan for a few seconds after the car is started....The other thing is even though there is power to the fan, the fan don't turn on even for those few seconds.

I checked the fan by running a hot and ground wire to two of the three connectors on the fan and it came on.

Again, I have checked all fuses in the fuse box, the 50amp radiator fan fuse, the ground wires, all connections I can see.

One last thing. There is an adapter of some kind that plugs into the fan which has two 20 amp fuses built in. This adapter is between the main wiring plug and the fan. I have ordered one ($90) but don't know if it's worth picking up and trying? The adapter changes nothing as far as the few seconds of power when the car is first started.

I certainly appreciate any and all thoughts, I am a blue collar, low budget guy and trying to save $$$ by figuring this out myself. Thanks....

The comment about charging the AC to the point where it will not accept any more refrigerant concerns me. You might have more than one issue that you're struggling through. It is possible to overcharge the A/C system, and as it gets overcharged it becomes much less effective. Additionally the system incorporates both an low pressure and a high pressure safety switch, so as the pressure builds it could be shutting off the clutch and therefore also shutting off the radiator fan. However, that would not quite explain the correlation to the engine running hot and the fan not kicking in....

I will take a look at the wiring diagram for the fan system and see if that triggers anything for me.

-Rod

I think you need to concentrate on the engine getting hot, not the a/c. Original radiator?

Oh, so one thing to consider is that the temperature gauge on the instrument cluster is driven by a different source than the PCM uses to determine when to turn the fans on. You might want to confirm that the Engine Coolant Temperature sensor for the cooling fans (uses a 2-wire connector, wire colors light green/red and gray/red) is working properly.

You also mentioned that you ran jumper wires to 2 of the three wires at the cooling fan. Maybe you only verified the low speed fan works while the high speed does not or vice versa. The Black wire at the fan is ground, the Brown/Orange is the feed for the Low Speed and the Dark Blue is the feed for the High Speed. To also check the CCRM and wiring from the CCRM to the fan you could backprobe pins 14 (Tan/Orange) for the Low Speed and 17 (Light Green/Purple) for the High Speed. I believe these are active low and would be triggered by grounding the signal. Using a test light would be the safe way to attempt to trigger the CCRM.

-Rod

I appreciate the help on this forum. I think I may have had multiple problems but after replacing the radiator fan (after I had tested it and thought it was okay) my problems are solved. Thanks again....

Glad to hear your issues appear to be solved. Thank you for following up with what you found the issue to be.

-Rod