2009, LT, 2.2L ecotech
Tried searching but didn't find anything. Cabin blower motor intermittently turns off and on when A/C is supposed to be on. Seems like it's when you go over a bump that it either turns on or off and it's usually off when you start it. I'm guessing either fan switch or blower motor. Is one or the other more likely? A fuse that I'm missing? Thanks in advance for the help.

 

Remove the hvac control panel and look at the back for melting plastic at the connections
look at the resistor connection for melted plastic
check the fan motor connection.
tighten the four bolts in the under hood fuse box , push all the relays and fuses firmly into place.
push all the fuses and relays in the interior fuse panel below the waterfall on the passenger side of the console.

 

Fuses, control panel, and blower connection all look good. I'm a bit stumped.

 

How so?

 

If vibration is the cause it must be a loose connection. Did it just start? Any work around the time it started? Does the AC compressor continue to run when the fan goes off?

 

I don't know if the comp clutch stays energized or not when it turns off. I haven't actually seen it then off myself. I've just been on the phone with the missus when she says that it won't turn on when the car is started or that it turns off and on a few times as she's driving. She's taking taking it on a trip in a few days and I didn't want her to have any issues. I can't get it to turn off to track down the issue.

 

Could be amount of Freon R134A in the system .

 

More than likely it is the blower motor (or connection) or it could be the resistor (or connections) if it usually happens after running for a bit.

 

It hasn't messed up yet. I pushed some fuses in a little. At least a couple that pertain to the AC system, both inside and under the hood. It certainly didn't seem like enought to be the issue. I guess we'll see. Everything looked good on the backside of the control panel. The blower resistor connection seems fine. I guess we'll just have to send it until we can get it to shut off when it shouldn't, and diagnose it from there. Thanks for all the help.

 

Naturally, while I couldn't get it to shut off all weekend, when I fired it up this morning, no AC. Back to the drawing board in a few days.