Question
Brian's A/C Panel
I'm so happy that I found you Ron!
I bought a beautiful 450SL in August and as I should have expected, I'm finding new issues everyday. I have the older, "manual" type vent controls, with the four levers and two knobs on the A/C dash panel. (see pic) The heat stays on HIGH on the right side, all the time. The blower is off, and I've closed the vents but I'm still burning up even with the top down. The driver's side occasionally does the same but if I move the lever up and down a few times, I've been able to stop it. What do I need to replace, repair, oil, etc.?
Also, the vacuum controlled locks only work once, maybe twice after the car is turned off. I have to restart the car to get into my truck, etc. Where are some common areas for leaks or could it be the vacuum pump itself? (The locking pin for the fuel door is missing.)
Thanks so much for any help you can give me! -Brian
Answerthe levers actuate a small on off switch in the down position that closes the heater valve. You may have to replace these . Te valve is vacuum driven . I actually retrofitted mine with some micro switches from radio shack, problem is you have to remove a lot to get to them. The other option is to manually close the heater valve . IT is located on the fire wall , drivers side. This may all be related to a vacuum leak . you really need a mittyvac to test all the lines , but I suspect you have a leak in the valve in the drivers door. That is common place or a disconnected line on the firewall dashpots..
Follow the vacuum lines from the vacuum pump and replace any lines that look old and cracked.
The best way for me to help is to be as specific and with pictures
Easier to communicate to me by sending direct to my email
fhfarm@gmx.com
The 77 is a nice car . I have rebuilt a few
Let me know how else I can help
Happy motoring
Ron
