I also have a diagnostic flow chart for problems with the servo-type climate control system. Can't say how it compares to Larry's info, but this is a good diagnostic chart that I used to help me cure my problem. I'm sure Larry's diagnostic info is good, the one I have is from a professional service manual. Let me know if you want it and I'll mail you a copy.

Good Luck!
Tom

__________________
America: Land of the Free!

1977 300D: 300,000+ miles

American Honda: Factory Trained Technician & Honor Grad.
Formerly:
Shop Foreman;
Technical Advisor to Am. Honda;
Supervisor of Maintenance largest tree care co. in US for offices in Tex.