Community Forums

max49 · 03-28-2010, 04:03 PM

On this last trip my heater will only blow out the defrosters. This is almost useless for keeping people warm in the cab area.
I know I've read that there is some kind of vacuum control. Is this under the hood or under the dash? Do these things go bad? Is it more likely a hose came off. Is this a WH part or can it be replaced with a Napa type part? Does anyone have a suggestion as to where I should look first? If I can't get it fixed right, right away, is there a way for me to manually put it where it would blow out the dash vents instead of the defrosters? This is where I always use it, whether for AC or for heat.
I'm hoping I don't have to remove the entire dash to get to this.
Thanks in advance for any help you can offer.

DAN L · 03-29-2010, 03:27 AM

Quote:

Originally Posted by max49

On this last trip my heater will only blow out the defrosters. This is almost useless for keeping people warm in the cab area.
I know I've read that there is some kind of vacuum control. Is this under the hood or under the dash? Do these things go bad? Is it more likely a hose came off. Is this a WH part or can it be replaced with a Napa type part? Does anyone have a suggestion as to where I should look first? If I can't get it fixed right, right away, is there a way for me to manually put it where it would blow out the dash vents instead of the defrosters? This is where I always use it, whether for AC or for heat.
I'm hoping I don't have to remove the entire dash to get to this.
Thanks in advance for any help you can offer.

the problem is probably a vacuum leak because when the vacuum is gone the system defaults to defrosters. the leak could be under the dash or under the front hood. my dash folds up for easy access. the small rubber connectors sometimes fall off or break. if you cannot see a bad connector or line, i have sprayed w40 or similar on vacuum lines to detect leaks.

you can turn the dash control off (it takes some vacuum to do that) and use the propane furnace while under way until you find and fix the problem.

TrekPR · 03-29-2010, 07:27 AM

I would check under the hood first. Look for colored tubes that can look like wires, RV manufactures went to this type and they do not hold up to the temperatures in the engine compartments. You should be able to find a vacuum pot usually round mounted to the fire wall. I also had critters chew through the vacuum line which runs from the pot to the engine. It took me some time to find the vacuum line and I had to remove the dog house to get at it.

Oklahoma MR C · 03-29-2010, 07:39 AM

Max 49, I have also a Intruder,as you may remenber and I also lost heater control. Found the hose at the Vacumn bottle had come off. Open hood and on your left side up, you will find the vacumn bottle. good luck!

max49 · 03-29-2010, 06:43 PM

Thanks guys, maybe it won't be a tough problem. However I took it to an auto/truck repair shop today. It's nice not to have them tell me they have an opening in June or something like that. They have worked on my other MH and they aren't cheap but I never had any more problems with what they fixed.
I'm hoping they are going to do the P-32 ignition switch mod for me too. I have an extended warranty that I've never used before so I'm hoping they pay for some of the total bill.
The lighting problem could be tough to find.

DriVer · 03-29-2010, 08:16 PM

Quote:

Originally Posted by max49

The lighting problem could be tough to find.

Max, I had absolutely no problem in finding my lightning problem!

kayo · 03-30-2010, 11:37 AM

I had the same problem with my 2004 Damon. Called the AC supplier for Damon who told me to look under the hood, and look for a softball size black plastic canister bolted to the top of the engine compartment. I found that the vacuum hose had disconnected, thus no vacuum to change the position of the dampers that control the direction of air flow.
Stuck it back on and all is well.