No dash heat

[Rickklem]

2017 ACE,
I am only getting cold air out of the dash vents. The heater hose from the engine to the valve is hot, the hose past the valve is cold and the return line is cold. Is there a way to test that valve or make it open?

This is a borrowed coach from my dad so I don't know much about places to get parts from. What is the part number for this and does Amazon carry it?

Also, the divertor is not working , when I change where I want to air directed nothing changes. Could this cause the valve not to open?

Thanks
Rick

 

[PS89]

The temperature control valve and the actuators share a common ground and a common power supply.

There's a 10A fuse in the Bussman/Thor fusebox under the left side of the dash that powers the HVAC's control system.

 

[Rickklem]

It is nearly impossible to get to that panel without removing the drivers seat. I checked the fuses and I didn't find a bad one. I did find a 6 or 8 gauge black wite that has a butt connector that was apart. I tried to jam the wire back into the butt connector until I can replace it later today , but it still didn't work. Unless the splice connector is still bad. I'm not sure what that wire is for other. I would like the fuse panel diagram so that I know what each is for, but not sure where to get it from.

 

[Rickklem]

I removed the electrical connector at the water valve under the hood and checked for 12v while the dial was set to hot. I had no voltage, but I do not know when the voltage is sent and how long it stays on.

 

[16ACE27]

I removed the electrical connector at the water valve under the hood and checked for 12v while the dial was set to hot. I had no voltage, but I do not know when the voltage is sent and how long it stays on.

Does your valve have a part number? Does it look like this?

It may be a motor operated valve (as opposed to a solenoid operated valve).

 

[Rickklem]

Yes, it looks like that. I took a picture but I can't attach it without a url to post it to. But the part number is Invensys 16923 or that 6 might be an 8. The other number on it is 127-00020-001 (80). Bit I don't know if it is bad if I'm not getting 12 V to it. I need to know if there should be a constant 12V when set to hot on the dial

 

[16ACE27]

Yes, it looks like that. I took a picture but I can't attach it without a url to post it to. But the part number is Invensys 16923 or that 6 might be an 8. The other number on it is 127-00020-001 (80). Bit I don't know if it is bad if I'm not getting 12 V to it. I need to know if there should be a constant 12V when set to hot on the dial

The second number scored a hit:

https://comfortairgr.com/product/comfort-air-motor-actuator-127-00020-001-80/

Motor actuator - probably a step-motor so probably only 12 volts to it when moving. Give ComfortAir a call. They took over the Evans Tempcon line and can probably help you determine what your issue may be.

You can also check out this troubleshooting guide:

https://comfortairgr.com/wp-content/uploads/2023/02/et3-evtg.pdf

 

[OldWEB]

Yes, it looks like that. I took a picture but I can't attach it without a url to post it to. But the part number is Invensys 16923 or that 6 might be an 8. The other number on it is 127-00020-001 (80). Bit I don't know if it is bad if I'm not getting 12 V to it. I need to know if there should be a constant 12V when set to hot on the dial

Sure you can, no such thing is "I can't" here!
How to post images

 

[craigd853]

The second number scored a hit:

https://comfortairgr.com/product/comfort-air-motor-actuator-127-00020-001-80/

Motor actuator - probably a step-motor so probably only 12 volts to it when moving. Give ComfortAir a call. They took over the Evans Tempcon line and can probably help you determine what your issue may be.

You can also check out this troubleshooting guide:

https://comfortairgr.com/wp-content/uploads/2023/02/et3-evtg.pdf

Hello, that part can be purchased on Amazon. Just plug in Tempcon heater actuator, there are two types depending upon plug configuration. Good Luck

 

[PS89]

Since neither the valve nor the shutter actuators are working, it would behoove you to look at elements that are common to both features.

If you jump straight to replacing the valve without considering the whole set of symptoms, you'll be posting in a few days saying "I replaced the valve and it still doesn't work"....

I removed the electrical connector at the water valve under the hood and checked for 12v while the dial was set to hot. I had no voltage, but I do not know when the voltage is sent and how long it stays on.

One wire should be ground, one should be HOT when ignition is in Run via the preciously mentioned fuse, and the other should be a variable voltage between 0 and 12 volts based on the position of the temperature control potentiometer.

 

[simidrm]

Those valves are pulse modulated. So you won’t get a voltage at the connector

 

[Rickklem]

Those valves are pulse modulated. So you won’t get a voltage at the connector

With that said, would I be able to put a V meter or test light on the variable wire and see something while I have someone inside the vehicle changing the temp valve?

Rick

 

[Rickklem]

I will check

Since neither the valve nor the shutter actuators are working, it would behoove you to look at elements that are common to both features.

If you jump straight to replacing the valve without considering the whole set of symptoms, you'll be posting in a few days saying "I replaced the valve and it still doesn't work"....


One wire should be ground, one should be HOT when ignition is in Run via the preciously mentioned fuse, and the other should be a variable voltage between 0 and 12 volts based on the position of the temperature control potentiometer.

I will double check the fuses again. I will also redo that ground connection that came loose at the splice.

Thanks
Rick

 

[PS89]

Those valves are pulse modulated. So you won’t get a voltage at the connector

I'd be interested in seeing documentation for this type of operation. I've been through the entire Evans manual that was published in the mid-teens and I haven't come across any indication of HOW the actuators are driven, whether it be via PWM or variable DC power. The diagnostic procedure for the temperature valve, for example, only gives expected DC voltages for the extremes of the control potentiometer rotation.

A DC meter should give a reading for PWM circuit but it's not going to be as readily interpreted.

Since the OP indicated there is no power at the valve, I'm still going to stick with my original assessment that supply power to the systems is missing or has been interrupted. An open ground might also be at issue, depending on what was used as a ground when making those initial measurements. Should have been referenced to chassis (vehicle) ground.