PeachParts Mercedes-Benz Forum - 1985 300D AC/ Heater Issue

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/)

- Diesel Discussion (http://www.peachparts.com/shopforum/diesel-discussion/)

- - 1985 300D AC/ Heater Issue (http://www.peachparts.com/shopforum/diesel-discussion/376393-1985-300d-ac-heater-issue.html)

1985 300D AC/ Heater Issue

1985 300D: up until yesterday my AC was working perfectly but the heater was working at times but then not. I replaced the monovalve with an NOS complete monovalve (new in MBZ package but about 20 years old - I did check the rubber diaphram and looks great, no tears and very flexible).

After changing the monovalve I now have constant heat but no AC. The compressor is engaging and yesterday I did have great AC. I changed back to the original monovalve but still have constant heat.

Any suggestions? Thanks.

You might need to tighten up, clean up the connectors, terminals to the monovalve.

Dirty terminals. Fixed the problem. Thanks.