Basics of heater function for my 64' c coupe

[Wes Bender]

When these Cs and SCs were new, you could obtain both interior heat and defrosting of the windshield at the same time, although the defrost was marginal when operated that way. To get good defrosting, pull the heat lever all the way back, select the off position on the dash lever and then close both sliding valves near the floor. For max interior heat, close the dash lever and open the sliding valves. It's all very simple.

Added by edit: For defrosting, the position of the dash lever only matters if you are moving. At rest and with the floor vents closed and heat on, heat will come out of the defrost vents with the dash lever in any position.

[Martin Benade]

So it would in fact send heated air to the windshield, based on the dash lever setting, correct?

[Wes Bender]

Yes. Those fresh air valves are a bit complex in their operation. (The valves are complex but the operation of them is simple.)

[Thomas Sottile]

SCR youse to sell auxiliary heater AKA blankets

[Greg Bryan]

While the operation is the same, the C had two types of heater systems. One is the 'USA' or 'RoW' style and the other is the 'Euro' heat system that was used in Germany and Sweden. I presume you have the USA type but plenty of the Euro systems ended up here - very distinct differences. Most obvious to the owner is that there is a snout that comes off the fan housing and large tube in the engine compartment of the Euro system.
The USA system has the flappers that you can see by peering at the underside of the engine. Both systems must have the linkage properly adjusted to put out max heat. Those procedures are in the repair manual for both systems.

[Wes Bender]

I edited my post #16 to correct one item on defrosting.... We don't often use defrosters in AZ.

[Ken Tuvman]

So for a B model (1961 T5) I only see floor vents - my heater is not hooked up yet - does this mean there is no defroster function & that wing vents keep fog off the front windshield?

[Greg Bryan]

There is a tube that runs from the longitudinal area to a defrost outlet on each side

[Ken Tuvman]

There is a tube that runs from the longitudinal area to a defrost outlet on each side

Thanks Greg - does factory manual show plumbing diagram?

[Martin Benade]

Whatever defogger it has, don’t expect very much action from it.

[Ken Tuvman]

Whatever defogger it has, don’t expect very much action from it.

Figured as much

[Greg Bryan]

I think the manual does have a basic drawing

[Wes Bender]

I think the manual shows the schematic of the levers, valves and tubes/hoses at the engine and they also show the fresh air valves that are in the luggage compartment, but I don't think the rear defroster or the actual routing of the air passages forward of the floor vents is shown anywhere. Obviously, if you had everything removed for serious bodywork they should be visible, but I've never actually seen them.

[Greg Bryan]

This is from the TSB introducing the 'Euro' heater system. More info in an article I did on the system several years ago. (V41-Issue 3 September 2017, page 64)

[Martin Benade]

Other than the engine, the car was identical with either heat type?