Misc. Heater System 1973 CJ5 V8

[Ironman]

I can't find a complete discussion on the heater control system for my 1973 CJ5 V8 operation that covers my question. So here it goes.... I would like to make sure I understand how the system works. Let me start by saying that all my control cables and mounts were removed and there were multiple other issues. I have everything fixed and operational except the cables. I am confused about their being a heater control valve that controls the flow of coolant to the heater. I can find parts that say it is a heater control valve that stops or limits the flow of coolant from reaching the heater core. I don't find and pictures or descriptions with one installed or used. The way mine is set up (and what I see in pics) is water pump to heater core, heater core to rear of engine. Coolant flows all the time. Is this correct? There is always a hot core in the cab and you just control air flow?

If this is correct, is there a problem with controlling a coolant flow control valve? One type is for the incoming side only and you control that flow with a cable. The other manual type of valve I find has connections for both sides (4 ports - in & out) and you can eliminate flow, effectively bypassing the heater core, be keeping that coolant pathway. If you only use he one side which is controllable, is there any issue with restricting or stopping coolant flow back into the rear of the engine?

Any thoughts on how it was designed to work and on either of the coolant flow options? Your assistance is appreciated!!!!

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[CJ]

I don't remember my 72 having a heater control valve. It was just plumbed directly to the engine. It's no problem adding one if you want to. Stopping the flow of coolant is ok. When my heater core started leaking I just capped the water pump outlet and plugged the intake port.

 

[Jeep Soup]

A control valve first pictured is the Most Common Style for almost all vehicle manufacturers.
It is a easy install if you don't have one.
Big Plus is there is No Hot Water being circulated in the closed position, which is Handy during the summer. Why need a Hot Heater Core inside a Small Vehicle when it HOT out to begin with.

 

[TSB8C]

Actually look at it as two separate circuits/flows: the heater/manifold circuit which always flows water regardless of the thermostat being open or closed. This is done for several reasons, the primary reason is to help the manifold get hot as fast as possible. The reason for this is that a heated manifold will help keep the fuel in suspension for quicker warm-ups and cuts down on SMOG. Second, it also helps with the windshield defrost cycle, and third it allows the water pump to circulate water when the thermostat is closed. The engine block circuit is controlled by the thermostat.

So there was no flow control valve in the heater/manifold circuit or flow path. That water flows through the heater core all the time. Whether you get hot air inside the vehicle depends on the position of the dampers using the cables. As stated, you can add a flow control valve and another cable to operate it; but you'll defeat the prior reasons I stated why there was not one from the factory.

 

[Ironman]

So a 4 poi t bypass would be better to keep that path intact without heating the heater core. Air control is great, but having a metal box generating heat in the cabin during summer isn't ideal. Yes, it is noticeable as I have had multiple passengers remakr on the heater being on.