Air conditioner - Heater do whatever they want

have a look at the fuse box
may be bad connection and when it was blowing hot there was no connection and because of vibrations it suddenly had contact again?
or may be less refrigerant in the system?

 

Melting Fusebox ........

 

The heater hot water valve under the pass side. It defaults open all the time. It grounds to close. It could be the automatic climate control. Mine has done this intermittent. Under the pass side foot panel, I was thinking about plumbing in a manual water shut off valve. I rarely drive my TR in cold weather.

 

One thing that will be a strong clue for where to investigate is if the passenger cabin air blower also stops working when the air (wrongly) goes hot (if the coachwork was moving when "it started blowing hot", the ram air effect will still bring air into the passenger compartment even if the blower is dead too):

If air (wrongly) goes hot, and the cabin air blower stops working = very likely a fried connection in the k white connector (or some other fault causing the whole AC system to lose +12V power).

If air (wrongly) goes hot, but the cabin air blower keeps working = a more subtle control (sensor, AC ECU, hot water valve) problem.

 

Spot on! +100

 

K white connector is under front bonnet. in the fuse box. Looking at the fuse box from the front. K white connector is top left, horizontal, under headlights and condenser fan relays

 

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The k connector is on the US Passenger side (RH side) of the TR fuse-relay panel as shown in the pic above. (Great, now I've got a new ***** -- the default location for photos is above the text, and the "attach" stuff doesn't work like before...)

 

Not related to this post. But can you tell me how to add arrows like above?

 

I just put the pic in an Excel file, add the arrows/text boxes/whatever, and then use the snipping tool to make a .jpg file out of the displayed Excel page.

 

Any news on your AC problem Softwareguy or what ever your proper name is ?