91 park avenue heater/ac control head

[dave1956]

My problem is that the ac quit working. The repair guy says that the ac system is charged and working, but control head isn't sending the signal. I found one at the salvage yard off from a 93 lesabre but it didn't work either, (I plugged it in right there at the yard) I have taken out the circuit board and looked for broken solder joints, but they are pretty small and hard to see. I plugged it back in while it was dismantled, and can make it lose power just by flexing the board a little, so I know I have a broken conection somewhere. I have looked on line, but can't find this type, which has the manual fan and temp. I have seen other posts with the same problem so I know that this is a common problem. Any ideas

[madmark67]

Hi... we got together on the same post a few weeks back. If you can flex the board & get it to come on, we have the identical problem. You need a bright light & a good magnifying glass to see well (at least I do!)I found 6 questionable joints & the main grounding joint, which is the big one with the heat sink on it, was really bad. re-did the small ones & Couldn't generate enough heat safely to repair the ground without a good chance of damaging something else. I ended up taking the nut off of the heat sink & using a ring terminal I attached a wire to it's location & ran it around the board to the other side & soldered the wire to the board directly. It worked perfectly... for a while...
NOW the buttons work properly every time, but now the fan doesn't work at all. Haven't figured if it is a switch, a fuse, the fan or what... I will continue the fight & will keep looking for a relpacement although I don't have much confidence in a replacement as it seems to be a pervasive problem. Keep posting as you progress & I'll do the same. Maybe we can get this thing fixed. good luck.

[slapout]

Well, let's add another of us with this elusive difficulty. When it blows AC, it will freeze you out. Problem is, its as though it has a loose switch. It will work fine then suddenly just stop blowing AC. Blower is then simply blowing room temperature. You may have AC going to work, and none on the way home. I've looked for a wiring short (since I also have interior lights that sometimes don't go out and a trunk that gets stuck in 'release') but have not been able to find anything as of yet. Hopefully, we can put all of our collective heads together and come up with a reasonable solution. I've not pulled the unit yet to check the board, but it doesn't sound like any one has had success locating and soldering broken connections on the board either.

[madmark67]

Well, I fiddled around with it some more & with some well placed taps & pressure I CAN get the system to work properly. The fan will sometimes intermittently drop out but a tap will get it back. It MUST be somewhere in the board, wiring harness, or control head. I will wait for the summer heat to break & remove the unit for further examination.