1992 Mazda 323 cooling and A/C fan question


I drive a 92 323 manual, and I am very happy with it. It is all stock and mostly trouble-free. I have a question about the fans around the radiator (and condenser): when should they run?

There are two electric fans:
1. larger fan with yellowish shroud (sits between the radiator and engine) that runs with the engine.
2. smaller black fan in front of the condenser (between the condenser and the bumper/front grille). It never runs.

The car runs fine (does not overheat) but the AC is just so-so (I converted it to R134A hence I lost some efficiency there). I believe the smaller fan should run with the AC. How does it behave on your car?

I had a problem some 15 years ago when the larger fan seized (slowed down) and melted the wires. I replaced the fan and wires. Then some 5 years ago I replaced the relay for that fan - it would sometime fail to turn the fan off after turning off the ignition. It was a relay problem because it would stop when I tapped on it.

I *think* the two fans are controlled by two relays in the passenger (right) corner of the engine bay (right by the hood hinges, in black dust boots). The one closest to the passenger has 6 contacts; it controls the radiator fan (larger yellow shroud). The one next to it has 4 contacts, and I believe is called AC compressor relay, part H45067740 (based on the pictures). My compressor works (turns on when I enable AC) but the smaller black shrouded fan never runs. When I jump the fan (plug 12V into the contacts) it works - spins just fine.

How/when do your fans operate? Should I go after the relay or the fan? Is there a better way to troubleshoot the problem?

Thank you,


The Diagram Dude
2002 MP5
I don't know about your car but on my 2002 Protege5, the condenser fan always runs when the AC is on.

Your fan works so it's probably not the fan. It could be your relay. You can test it and see if it clicks when you have 12 V applied to it, assuming you're looking at the right relay and have a pin diagram for it.

You can test the wiring harness where the relay plugs in and see if there is 12 V getting to it when your AC button or switch is turned on.

Your problem may be that the AC control unit isn't sending the 12 V signal to the relay when your AC is turned on.

If you have a hard time tracking down the problem, you could wire a switch in your dash from the battery directly to the fan and control it manually.
Make sure that you use a heavy duty switch.
There could be 10-20 Amps running through it.

That's what I did on my 83 Mazda GLC.
The thermo switch failed and wouldn't turn the fan on so I just wired a switch into the dash.
I had to be careful to shut it off when I turned off the car or I would kill the battery.

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