I hope this hasn't already been covered, but driving the suburban Sunday (not by me, son in law) says the rear ac is cold, but the front isn't hot, but not cold. I replaced last year the blend door actuator as the driver side vent on ac would stop, and blow hot. I am sure (trying to remember) there are two servo actuators under the center console dashboard, is it possible or am I thinking the other one is stuck partially in the heat mode?

 

Any help with this?

 

Ok, looking into this issue, and I hope if someone knows will confirm this. I understand there is a blend door actuator for heat/ AC, I am thinking this (I replaced the servo a year ago) also is vent. The other servo actuator is for the air direction, floor, vent defrost, is this correct?

 

I had the same problem with our 2002 Sub.

I replaced the blend door actuator with one from Rock Auto and that didn't fix it.

Finally, I replaced the AC/heat control panel with one from a local junkyard and it has worked fine since.

There is a way to put the actuators into a test mode where they cycle from one end of the travel to the other. I think you pull the AC/heat fuse and then reinstall it after doing something else.

Try googling something like "suburban door actuator cycle test" .

Steve

 

Thanks. As it turns out the system was 1 .5 lbs low on charge. I must have a small leak in the system.

 

I have a small leak too.

The mechanic has not been able to find it with leak tracer, so it might be in one of the evaporators.

A few times during the summer season I have to top it off with an "AC Pro" bottle.

Steve