Most likely you have a bad air mix door actuator. It is not normal to do a diagnosis every time.

Jeff... You may want to check the freon level with a gauge and the FSM for proper pressures. However..this topic is Boreas and his system.

Bill both he and I have eleminated the air mix door actuator by forcing it to the cold side. Freon is fine. I have seen this on Bonniville'* since new, they just seem to be lacking when it is really hot out.

Jeff

I have a bad Airmix door actuator, and currently have my airmix door locked in the full cold postion. It has been over 100* for a month now (although we have very low, single digit humidity), and I never have problems cooling off my car. Most of the time, after 20 minutes of driving, I am turning down the blower motor to keep from getting too cold. I assume, the higher humidity levels that others experience has a lot to do with the cooling properties of the system.

I thought remember reading a few posts about cleaning/flushing the evaporator in the firewall. This may be another possible solution to check into.

I am a little stumped at this point. I would bet for sure it was the airmix door not fully closing. :?

Echo. That sounds right. Cleaning out that evaporator on the firewall isnt that hard. Do we know if he checked the lines we checked that were clogged or is this something different?

This is something different. Whereas you and I had cold air, but coming from the wrong vents, temperature is controlled by the airmix door actuator operating the airmix door, which is electronically controlled.

Also, with the airmix door arm removed and the airmix door manually held all the way toward the driver'* side, he should have cold air.

Thanks for the thoughts, ill be looking into that unit.

Well it did get cold, but only after 15 minutes of on time. Then after a power cycle it does its diagnostic thing and I loose cold air again and it goes back to mild. So in the meantime I did my own redneck fix:

http://www.clanmob.net/hosted/bonnev...neck+AC+Fix%2F

OK, so with the "redneck fix", you are keeping the mix door open to cold, but are you getting the cold that you should get and used to get?

I'm starting to wonder about the ECC and programmer at this point. If your actuator is known good then it'* in the control of the unit.

That'* what I'm trying to get at. Just wanted to verify if that is exactly what is happening.

Waiting on Boreas' input.....