300CD Climate Control
Thread Starter
Joined: Jan 2008
Posts: 3
From:
300CD Climate Control
Help, 1984 300CD Turbo. I Want to drive the coupe, but January in MD can be cold. Last year I replaced theclimate control valve (all was well)on the firewall. Now I haveno voltage, at the valve, in a/c, heat, and auto. Is this the climate control valve. Have checked all fuses. Coolant good, all other operations are normal. This was my dad's every day car, and I would really like to get it right. Thanx, GEO
Senior Member
Joined: Jan 2008
Posts: 408
From: Carbondale, IL
RE: 300CD Climate Control
howdy,
I have an '82 300CDT. I don't know if the climate controls are the same or not, but I suspect they may be. What I did on mine was pop the face plate off the center console, remove the 5-6 screws and take out the control module. After unsnapping the peripheral controls (the wheel and the fan switch) you can unsnap the cover for the control module itself. This is a fairly low-tech device and is your basic solid state bread board with printed circuitry and some relays and whatnot that make up the controls. A quick visual inspection will reveal any broken connections that can be soldered over. I had three that required it and that fixed all my problems (as well as replacing the valve innards on the firewall - broken diaphragm). Just be sure not to solder them to any other pathways. When I put mine back together, I also used a small sharp pick to push the female ends of the electrical connections in on themselves a little so they would make a tight connection when I put it all back together. If worse comes to worse, you could probably replace the whole module if you had to. I don't know what a new one would cost. Do you have any other indications that there is something faulty with it? Do the different fan controls and switches work?
Your other possibility is a faulty temperature probe under the dash. I have not replaced mine, but you can google the job and instructions will come up.
I hope this helps.
Matt
I have an '82 300CDT. I don't know if the climate controls are the same or not, but I suspect they may be. What I did on mine was pop the face plate off the center console, remove the 5-6 screws and take out the control module. After unsnapping the peripheral controls (the wheel and the fan switch) you can unsnap the cover for the control module itself. This is a fairly low-tech device and is your basic solid state bread board with printed circuitry and some relays and whatnot that make up the controls. A quick visual inspection will reveal any broken connections that can be soldered over. I had three that required it and that fixed all my problems (as well as replacing the valve innards on the firewall - broken diaphragm). Just be sure not to solder them to any other pathways. When I put mine back together, I also used a small sharp pick to push the female ends of the electrical connections in on themselves a little so they would make a tight connection when I put it all back together. If worse comes to worse, you could probably replace the whole module if you had to. I don't know what a new one would cost. Do you have any other indications that there is something faulty with it? Do the different fan controls and switches work?
Your other possibility is a faulty temperature probe under the dash. I have not replaced mine, but you can google the job and instructions will come up.
I hope this helps.
Matt
Thread
Thread Starter
Forum
Replies
Last Post
