Cruiseliner Transformation

[Geoff Weeks]

The solenoid is likely a continuous duty solenoid to switch power on with the key switch without all that power having to pass though the key switch. 

[Geoff Weeks]

Getting back to the coolant valve. Could you post a picture of the heater/AC controls? If it is the Red Dot control I am thinking of, the air would come from it, when in Max A/C.

Red Dot made lots of the heaters for trucks and would stencil the truck makers name on the controls. The one in my Marmon IIRC has one port that has air in the A/C position. Some one might have disconnected and plugged it at the control.

[fjh]

1 hour ago, Geoff Weeks said:

No air = valve open, air to the valve = valve closed.

They can stick, and leak as can any valve.

I used them for heater and fuel heat control. They make air switches that look a lot like electrical switches from the front end, to control them manually

those valves are "directional" in that they are only supposed to be used with the flow in one direction which is marked on the side of the valve with an arrow.

While they can fail, I wouldn't say it is a common problem. I've used them for decades and not had a failure. I've had cable operated valves fail also.

Note: those are either open or closed, there is no part way or throttling to adjust heat. 

Some A/C controls will supply air to the valve when in "max A/C" to stop all coolant flow in the heater core for better cooling. 

If you want, you can bypass it and see if you get heat, just put a straight tube between the hoses.

I often see them in bunk heater -A/C units to turn off the coolant to the heater core when not in use.

Yup on the money there bro! In the mh era these used to be one of those things you checked for before chasing a head gasket failure on the E9 !

[cruiseliner64]

Thanks for the replys.I will post a picture of the heater A/C controls as soon as I can.As our summers are not that warm A/C has only become popular since the EU mandated it for all new vehicles in the last 15 years or so.As a result Iv not much experance with it so decided to ask before just tearing it apart.I will bypass that tap and see if it gives any heat.The electrical switch does power up one side of the fusebox when the key is turned on so I think your spot on with that Geoff.Thanks again for all the replys....

Paul

[mowerman]

Good luck Paul. I really don’t have anything to add on this one…. Bob

[mrsmackpaul]

If you justran the truckup to temp and felt each side of the tap

This would give a good indication ifthe tap is working or not

Is there shutters on the radiator ?

If there is, do theseworks

If the water in the cooling system isn't getting warm it won't matter about the tap

Personally I don't really ever have a need for a heater in a truck, sometimes on very rare occasions it does get chilly 

So first things first, water has to get hot 

Then the tap has to be on

Then some air movement 

And presto, a warm cab 

 

Paul 

 

 

[Geoff Weeks]

My guess is there is another valve (likely on the block) or a valve controlled by a control cable that is not opening. I could be wrong, but if bypassing that valve doesn't work, follow the control cable to the valve that regulates the heat. make sure it is moving. Then check the valves on the block and make sure they are in the open position.

[cruiseliner64]

Yes Iv had the engine up to working temp.There is no rad shutters on this truck.Theres no air going to the heater tap to operate it.We got a short break in the rain this morning so I went out to get some pictures.I removed the dash panel covering the air con unit.in the pictures you can see the lower lever to change from cold to hot is connected to a resistor which is then connected to an air/electrical switch.The two pipes on the right are connected to air pistons to operate the air direction flaps,the pipe on the left is the air supply and the upright pipe behind the wires is connected to the heater tap.It doesnt matter how the levers are set no air goes to the heater tap.Im thinking its the air/electrical switch or the resistor thats faulty.The air supply and air direction flaps work perfectly.Id appreciate anybodys opinion.Thanks 

Paul

[Geoff Weeks]

wow, completely different then what I was expecting and very different from the Red Dot systems I am used to on other trucks. 

You can forget most of what I wrote! Sorry if I led you a stray.

Without those diagrams you'd be really up a creek!

It looks like an early attempt to make an "electronically controlled " temperature system where you set it where you want it it controls heat and AC. 

I have never seen one like that, and there are many things that could be wrong. Worse, I have never seen PARTS for a system like that, esp the CTC board and such. 

May be someone else here has more experience with that system, I have never come across it.

I believe CTC is an acronym for constant temp control. It looks like it uses a thermostat, resistor and board a long with air pistons and that air valve to control the heat and A/C. 

I think if worse comes to worse, find a way to bypass most of it so you have heat, and install and air switch to the air coolant valve so you can turn the heat off.

They may use the CTC system to control frost on the AC evaporator, so to make the A/C system work (without the present system)  you may have to install a frost switch. 

If no one here can help, I'd write Red Dot and see if they can be of any help. 

[Geoff Weeks]

With out that air controlled coolant valve connected, (in the open/no air position) from what I can follow on the diagram, you should always have full heat. 

If you are not, I suspect someone installed another valve that is off, it may be the valves on the engine block, or it may be something they installed to control heat themselves and will not be on the drawing.

[cruiseliner64]

Thanks for the reply Geoff.While I do understand the basic operation of an A/C system Iv no hands on experence of them.I'll dig a bit deeper see what turns up...Its very interesting to get to work on one!!!!

Paul

[Geoff Weeks]

I took a screen shot of what the Red Dot manual has to say about diagnosing the CTC system. I also attached the manual. Neither are of much help the CTC is on page 131

Red Dot Manual

[Mark T]

That switch at the end of the cable almost looks like something you'd find on engine brake controls .

[Geoff Weeks]

I did some digging in an older MEI Airsource catalog and came up with some stuff! Never noticed it before.

There are two CTC resistors  One looks like just the replacement (#1180) and the other is a "kit" with some mounting brackets (#1181) 

They also list a CTC control module (#1184)

However, a word of caution. There is the CTC and CTC II system according to the Red Dot manual and I am not sure which these are for, or if they are still available. I get zero hits on a web search.

That is about as far as I can get. 

[Geoff Weeks]

Found an online Red Dot catalog and punched in the number for the controller and they don't even list it in the parts section so suspect it is NLA from Red Dot and not likely from other sources. Bummer.