10-05-04, 09:27 PM
This thing is located behind the glovebox on my 1968 Deville. My Heater wont turn on but when i cross the two vaccume lines on this the flapper opens and i get hot air. Its either this part that is wrong with my heater or whatever controls the wire that goes to it. The part number on it is 7315 6826. I opened it up and I've never seen anything like it so i put it back together. Theres also an adjustment on the electrical end but all i can do with that is open or close the flapper. There's no control with the climate controls.
Thanks for any help
10-07-04, 01:02 AM
Ouch. Well, that little part there is your transducer. It's the heart of the climate control so to speak, the bridge between electrical and vacuum. What happens is the three temp sensors, and the knob on the dash are all wired in series, and the combined resistance is fed into a DC amplifier, which is connected to the transducer. What you actually saw was a specially calbrated heating element, which modulated vacuum to the power servo through a couple inches of mercury to set what mode the system should be in. As you found, higher vacuum to the servo equals more heat. Since yours was apart, wether or not it was at fault originally, it is probably way out of calibration (your cautioned to not even drop it in the service manual) Luckily, there are rebuilt versions available! (odd that something is actually available for these things...) check out http://www.usapartssupply.com/ thier catalog is invaluable with these cars! Anyway, $107.85 rebuilt, with a $100 core deposit.