Hello everyone,
I have been troubleshooting a problem with my daughters 1988 760T climate control. I've seasrched the FAQ, but have been unable to answer my own question.
Here is the deal: The problem is "no air out out the dash vents, only default to windshield and feet". I have narrowed the problem to a lack of vacuum at the vacuum reservoir under the dash on the passengers side. There is the electronic vaccuum diverter which controls air to the various damper doors located on the passenger side under the dash. On the diverter is a plastic manifold of 7 taps. The center tap which has a white vacuum line is the source which comes from the vacuum reservoir I previously mentioned. I found if I remove the line from the vacuum reservoir and supply vacuum to the diverter center white line with a tester, everything works as it should. With the car running, there is no vacuum at the vacuum reservoir. My question is,"Where does this resevoir get its vacuum source from?".
I noticed that upstream of center tap of the diverter(vacuum in, the line has a vee/tee. One side goes to the vacuum reservoir, the other..??????????. This could be the vacuum source??????? If so, where does it originate?
Any input is welcome.
P.S. I checked all the vacuum connections at the firewall on the passengers side, and all are ok at that point.
Steve