I discovered that my original issue with the monovalve was due to a faulty voltage regulator and bad battery. After replacement of the regulator and a new battery install everything seemed to be working just fine.

Until.....that is, this afternoon tooling home up the Interstate in 100 degree temps with the AC on full blast we hit a little bump in the road and almost immediately I am blasted with super hot air coming from the vents. After 10 or 15 seconds it began to cool back down but it took a minute or two for the AC to overcome the sudden furnace blast and get back to normal cooling temps at the vent outlets.

I figure, either I have a loose electrical connection on the monovalve that briefly came loose or the monovalve is mechanically weak and the jostle allowed flow through the heater core for a short time.

__________________
Joe

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1980 300SD - 495k miles - 'The Ambassador'
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Former Family Members
95 C280
73 280SEL
90 300D
87 300SDL (X2)
86 560SEL
84 300D
80 300SD