markbowles

09 HHR Panel

Having trouble with my ac clutch coming on. Seems to have a mind of it's on.
Replaced the pressure switch, Freon drained, vacuumed and refilled. Coolant and fan is cycling like it should. Cools real good when it's running.

Radiator fan does not come on with the AC turned on. However it does cycle with the cooling system - - so I know it works.

I can jump start the clutch to get everything going at the pressure switch. Even the fan will come on when I do this.

Only thing I've found that seems unusual is the fan relay if very hot to touch.

Sound like a problem ?

Thanks
Mark

FYI - - I did an intro but, I don't see it posted ....

donbrew

What fan relay?

Is this an SS?

I am a bit confused; The cooling fan does work. The A/C compressor is intermittent. There is no Check Engine Light.

Has anyone thought to hook up a gauge set?

Relay #15 and diode #9 on the underhood fuse box should be checked.

Could even be the swith.

markbowles

It's not a SS.
Radiator fan relay #50. I switched it out with the rear window defogger relay tonight.
No check engine light.
Yep - - gauges on it but, I think the high side gauge is not accurate. Low side is good. Cools goods when running.
Relay 15 is good - - switched it with a known good one. #9 diode - - I have no idea how to check it...

Started fresh with a cool engine tonight. I think something is screwy with the fan circuit.
First start up - - turn AC on, compressor engages, about a 5 second delay and the condenser/radiator fan kicks on as it's supposed to.
AC cooling perfect. Switch to defroster - - compressor and fan continues to run. Still cooling.
Now - - - turn ignition off and back on. Compressor comes back on but, fan will not come on. This has got to be the problem. I think once the cooling fan cycles off - - it won't kick back on resulting in high pressure which kicks the AC / clutch off.
My high side gauge stops at 120 - - I know it's getting much higher.
I'll get a new gauge asap.

Thoughts ???

Mark

donbrew

You check diodes with a VOM in continuity mode, should get continuity in 1 direction but not in the other.

I know the fuse box diagram says #50 is the fan relay, but it seems to be not there in most instances. I am not sure about it.

The diode works to keep the relay from "latching". That is why I'm looking there.


That was the problem with one last week.

markbowles

Sounds like this might be the problem.
Do you know if the fuse box diode is the only diode in the fan circuit? I read somewhere else that a diode was in the fan harness. Maybe that was an older model and GM (or whoever) decided to place it in the fuse box. I cannot seem to find a good diagram for this car. Probably a good thing since I'm a caveman when it comes to diagrams ...
Also - - the #50 relay is in place on mine and the cover is labeled as such.

Thanks again

Mark

donbrew

Now I'm getting confused again.

#9 is the diode for the compressor. You might have a diode in the fan wiring harness near the connector. Here is the thread that was in. That diode was supposedly in only early 2006?
https://www.chevyhhr.net/forums/prob...wn-fuse-58713/

When you switched the relays did the rear def work?

Could be the fan is trying to go bad.

markbowles

You're correct - - the #9 diode is not for the fan circuit. I do have the little gadget mounted on the radiator (diagram with the "M" circled).

I did not test the rear defogger - - I suppose the window will get warm if it's working.

The fan may be the beast - - I hate just changing parts .........

aradmahogany

The fan itself operates either on or off I believe. If it can turn on, generally it isnt the problem. I had to replace my fan in my LT, and it was a fairly simple and easy job, but thats because I broke a fin off of it by mistake.

donbrew

Some motors can have a bad bearing and work when cold but the bearing expands when hot, so it draws more amps to get started. Which might lead to a hot relay. Just a wild guess.

You could hot wire the fan to test it, cold and hot.

Another thought; Ammeters are a pain, do you know how? I don't.

markbowles

True - - pretty sure it's the original with 145,000 miles.
New fan assy is $72 at the local Oreillys and they actually have one .......