I'm having problems with my heater not working.
I have removed the vacuam from the heat valve and pluged the line. This should let the valve remain open. The ube on the cabin side is hot telling me that hot coolant is feeding into trhe cabin.
With the control wheel all the to the red setting, after driving several miles, the heat comes for for several miles and the cools off to blowing cold air. Then later it may or may not start working again. It is so unpredictble.
The same thing happens when I use the defrosters.
Is there some way that I may tie a flap open to get heat until I can pull the dash to fix whatever is wrong?
When I push the down arrow button on the control, I can hear a flap engaging. But still get cold air.

Any suggestions will be appreciated!

Tom Wiggins :

I just found this out... loss of vacuum default is full heat out the defroster (close the floor vent).

__________________
5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)

Tom- do a search on the forum. There is some pretty good stuff. The vacuum control module is under the passenger side A/C duct, accessible by taking out the glove box. You really need to get ahold of a mitivac so you can check for leaks on the lines leading out of it. It can be a bit daunting the first time you yank it out with all the lines and such, but just keep track of what you are doing and check each one for leaks. As I said, there are some good posts on the subject. Just as an FYI, it IS possible to set the potentiometer without taking the dash out, but it is not easy.

Bill