Thread: HVAC Mode Selector , A/C Light and Blend Actuator

Originally Posted by turbojimmy

Okay I fixed it today. It's a bad news, bad news, good news story.

Bad news is that after removing the old blend door actuator and manually rotating the door all the way to cool, it was still warm on the driver's side.

The other bad news is that the $20 replacement actuator motor I got directly from China was wrong anyway. Pins were different. I plugged it in anyway and it did nothing.

Good news is that the real problem was that it was low on refrigerant. Apparently the A/C system overcomes quite a bit of warm air that gets mixed into the air stream. It was 90 degrees out today and the passenger side was cool but not cold. On a hunch I hooked the gauges up to it. Pressures were low and there was evidence of ultraviolet leak detector in the system. It took 12 oz of r134a (all I had) and the pressures are close to where they should be. NOW the A/C is COLD cold on both driver and passenger side. I think the leak is the high pressure port which will suck to replace. I'll have to monitor it and see how quickly it leaks down.

Definitely get that leak fixed asap. running the system like that could destroy your compressor or worse. I'm lazy, so I always inject some uv dye into the system to find the leak quick. Everything other than the dye and refrigerant you can rent at autozone. It's really easy. If the leak is the connector, it's almost 99% always the schrader valve which is easy and cheap to replace. Just make sure you vacuum the system for an hour, let it sit and watch the gauges to see if the leak is gone, then charge the system (don't charge on high side) and enjoy!

Yes it is the Schrader valve that's leaking. I wonder if it's my gauge kit that's doing something to them. It's a new kit that I've only used twice and both times I wound up with leaking Schrader valves. First time was the low side valve on our Jeep and now the high side on the Pontiac. Neither were leaking when I started. I had vacuumed the Jeep down and it held the vacuum overnight until I recharged it. But then after charging the low side valve leaked. The cap stopped it, but they're not designed for that I don't think (though they do have o-rings in them so they're more than just a dust cover). I checked on it a few days later by removing the cap and it had stopped. Hopefully the same will happen to the GTP.