2008 HHR LS, my ac starting blowing hot, then it will go back cold, then hot. It seems the cooling fan (behind the radiator) it not coming on when I turn on the AC. The cooling fan is only coming on when the engine get's to a certain temp. Any help is greatly appreciated already 100+ heat index in Houston.

I feel like there should be switch, fuse, relay, module that I have failed to check...

.thanks.

 

Moved to a new thread.
Normal operation is that the fan does not run until the temp reaches 219F or whe the AC compressor is running.
Is the CheckEngineLight on? What is the engine temp according to the digital gauge. What is the "certain temp, why is it secret?

 

Check Engine Light is NOT on. No secret, I just did not pay attention to the temp. I will make sure to see what that temp is.

 

I responded to your PM.

 

If your digital temp is below 180F you need a new t-stat.
Could the ambient temp is high enough that the temp increases fast enough to satisfy the ECM. Then when driving the temp gets too low for the AC to run, in that case there would be a pending P0128 that would not set the CEL or be there on the next startup cycle In other words only while the engine is still running and the AC is supposed to be on.

 

What have you checked and what were the results.

 

ok test done. Parked in driveway, start engine, turn on AC full blast, nothing but hot air blowing, cooling fan behind radiator not running, sit and idle a bit, cooling fan behind radiator turns on at 118 degrees, ac compressor kicks on and we get nice cold AC.

Do we still think I need to replace the fan to fix this issue?

 

I don't see where anyone suggested a problem with the fan. Sounds more like a problem with the AC. You should have a pro put guages on it to diagnose.

 

Why would you replace something that is working as designed? The fact that it is getting to 118F is not telling in Texas, the hottest place in the country now.
It is the AC that has a problem. Has anyone mucked about with the switches on the waterfall? Did the CEL light up? Did you check for pending codes while the test was being done? What is the digital temp while driving? How cool was it when the fan turned off, did the AC run all the way down?

 

What is the "waterfall"?
What is a CEL light?
I did NOT check for codes.
I will drive it and see what temp we get to & what temp it cut off at.
I an not sure what you mean by "run all the way down'?
I did put a guage on it while compressor running and ac cold, is in the green.

Someone suggested replacing the fan...(it will be here tomorrow)I thought maybe there was a secret fuse or relay between the ac and the fan that might be out...