Dash Heaters

[hadolex@shaw.ca]

We have a 1999 HR Imperial with a 350 Cummins.

The dash heater has been looked at and deemed in working order. However during winter months travel it does not heat the cab. It feels lukewarm at the vents. We are forced to use our furnace to make it comfortable.

Has anyone experienced this issue?

Lex

[wolfe10]

Lex,

Do you have a motor-aid water heater (engine coolant warms your hot water)?

If so, they are normally "T"'ed off the line to the dash heater. Many coaches with motor-aid water heaters (including ours) have a valve in the line to the water heater than can be shut off to force more engine-temperature water to the dash heater.

And part of "checking it out" would be to remove the hose from the water control valve (front of coach) and verify that the heater temperature control fully opens the valve when set to HOT.

Brett

[pweaver123@gmail.com]

Brett.....where do you find the valve? Would you look under the dash, in the front firewall area, or under the coach?

I too FREEZE in colder temps......figured it was just the "nature of the rear engine beast."

thanks

Paul

[wolfe10]

Brett.....where do you find the valve? Would you look under the dash, in the front firewall area, or under the coach?

I too FREEZE in colder temps......figured it was just the "nature of the rear engine beast."

thanks

Paul

Paul,

The valves are in different locations:

If you have a motor-aid water heater, the valve to shut off hot engine coolant flow to it which forces more hot engine coolant to the dash heater would likely be near the water heater.

The water valve you control from the dash HVAC control should be in the front of the coach, near the heater core. This is usually on the passengers side and can generally be seen by accessing through the "nose".

I have also seen a few older coaches with a valve in the heater line back near the engine. Its purpose would be to shut off water flow to dash heater (and motor-aid water heater if equipped) in case of a leak in that circuit.

Brett

[wolfe10]

Another option is to install an electric booster pump to force more engine hot coolant to the dash heater.

Here is one I found using Google: http://www.daviescraig.com.au/Electric_Wat...ps-content.aspx

Their smallest pump even lists as one of its uses: "Heater Booster Pump – The EBP® increases heater performance during normal vehicle operation............"

Brett

[BernieM]

Lex,

We have a 2000 Monaco Windsor... we noticed that it gets nice and toasty only when in traffic at idle... which is when a shop would be looking at it and saying all fine!!! As soon as we get a crusin... it is no longer hot.... I suspect our vacuum system is not holding the doors open correctly or enough??? I know in a car, a vacuum issue with the big black softball under the dash area is usually an indication of low heat also.... We have a "black box" that is part of that system with a little valve that is leaking air.... can't find just the valve... Monaco wants the entire assembly for $200++....... don't know if this helped or confused..... but just be sure you have a good vacuum source to the black sofball all the time....

[wolfe10]

Lex,

We have a 2000 Monaco Windsor... we noticed that it gets nice and toasty only when in traffic at idle... which is when a shop would be looking at it and saying all fine!!! As soon as we get a crusin... it is no longer hot.... I suspect our vacuum system is not holding the doors open correctly or enough??? I know in a car, a vacuum issue with the big black softball under the dash area is usually an indication of low heat also.... We have a "black box" that is part of that system with a little valve that is leaking air.... can't find just the valve... Monaco wants the entire assembly for $200++....... don't know if this helped or confused..... but just be sure you have a good vacuum source to the black sofball all the time....

Bernie,

"Lack of vacuum" would show up as air flow changing from coming out the selected vent to the defrost vents which are the default location.

Brett

[jmgrigsby]

I have the same problem - my dash heater blows cool air. And when I turn the knob to "feet" it blows out the defrost.

I don't think I have a motor-aided water heater. I have also had problems withe the dash a/c - not cold enough. Are these problems related? I'm new at this - what are you suggesting that should be done?

[wolfe10]

I have the same problem - my dash heater blows cool air. And when I turn the knob to "feet" it blows out the defrost.

I don't think I have a motor-aided water heater. I have also had problems withe the dash a/c - not cold enough. Are these problems related? I'm new at this - what are you suggesting that should be done?

Jim,

Find out the company that made the dash HVAC unit and controls. Most have excellent troubleshooting manuals-- many on line.

This could be a controls issue, leak of outside air issue, etc.

And, when you say the dash A/C is not cold enough, what is temperature out the vent with the A/C on high fan and recirculate and what is the temperature at the air return duct? That will tell us if the A/C is performing up to spec. Let's face it, the dash A/C is not large enough (in terms of BTU's) to cool a coach, so A/C performance is not up to expectations if based on one's experience with cars/SUV's.

Brett