Constantly running AC cooling fan but no Primary fan

[turbojon]

I haven't driven the LSS in a while for a long distance, but the other day when sitting in traffic/drive-thru I noticed the temp gauge going higher than normal. Normally while driving around, the car would rarely go over 190 (I have a 180 thermostat). It probably hit around 230+.

When it went up, we were stopped at a drive-thru and I had the AC going. When I left there it immediately started falling, which made me think it was a cooling fan issue.

Sure enough, when I got home and popped the hood, the fan on the driver's side (I assume the primary fan) was not on. The smaller fan on the passenger's side (I assume is the secondary AC fan) was on.

After a few days keeping an eye on it, the primary fan NEVER comes on and the smaller fan ALWAYS runs. No matter what the A/C is doing-on or off- and no matter if the engine is hot or cold.

The only trouble-shooting I have done is:
Tried unplugging the coolant temp sensor, as I read this might trigger all fans to kick on (nope).
Tried switching out the relays (low speed and high speed) and swapped out the low speed with a known good one out of another car (no change).
Checked the fuses for the cooling fans, and all looked fine.

I have access to another free cooling fan to try, but I was wondering if anyone knew why the small passenger's side fan was running non-stop. Or is this a safety precaution that the computer tells the fan to always run if one is testing bad....or is this a sign of grounds/wiring/pcm issues ?

Thanks for any insight, guys.

[RJolly87]

To clarify operation, both fans come on at the same time. The 'main' or bigger fan, is dual speed, and the smaller secondary fan is single speed. When low speed is requested, main fain goes to low, secondary fan is commanded on. Then with high speed, the secondary fan remains on, and the main fain switches to high.

Check for power at the main fan, assuming it even spins freely. I believe that power for the two fans splits off relatively late in the circuit, so the issue is likely near the fan motors (if not the motor itself). If you have power at the main fan, but no spin action, it's likely the motor. Test light will likely be your weapon of choice in these parts.

Unplugging the temperature sensor should force the fans to high as a fail safe, and hopefully should make diagnosis a bit easier. I recommend against running the A/C while not moving, especially in stop-and-go, until you can get this tracked down. A/C Headpressure can run away real quick, and while there are safeguards to prevent serious explosions, you aren't doing your compressor any favors. Thankfully it should be pretty clear cut, so it should be easy to track down.

Happy hunting!

[turbojon]

Thanks for the response, Randall. I am hoping it is just the fan motor. Good thing about my Dad being a pack rat. He has his LSS he wrecked 8 years ago in his back yard.

I am currently not driving the car. With the 90+ temps my Neon has been driven due to it's ice cold AC.