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Dash heat and fan speed

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Don Forsyth:
I have a 2005 Beaver Monterey Laguna IV with Cat C9 400
I have had the camper for three years now and have done a ton of work on it. I noticed at first that there was no dash heat and the fan would only operate on high speed.
I thought at first that there wasn't any dash air conditioning but figured out it just need to be serviced and charged.
I checked all of the controls for the vents and they are operating correctly.
I read a couple of different posts on here as well as IRV2. About the fan rheostat being defective and should be replaced. I have looked under the dash, pulled the drawer in the console and even pulled back the panel next to the stairs, but could not find the rheostat. Someone said it may be up between the firewall and front cap. I poked my head up there and decided to retackle at a later date. Its time.
I crawled up in between the front cap and firewall. (Man is tight, not much room to move) See the pictures attached. This is what I found. Someone, maybe the previous owner has clamped off the heater hose. I can only guess at this point as to why. The camper lived in Florida the majority of its life. So did they clamp it off because it was blowing hot air all the time?
Or is there a leak? The pliers are out of my reach. I tried stretching up in there but no go. I started wondering if the may be an access panel in the top of the dash to come down from the top. If you look at the upper left side of the picture it almost looks like something sealed up.
So I did get part of the dashboard off on the top. But not the part along the windshield. It appears to be held down on the two outside corners. I tried pulling back the vinyl trim next to the windshield, but it did not reveal anything. i thought maybe a clip or something, or is the windshield gasket holding it? If there is an access panel it is under this piece and I don't want to break or damage it. I am also guessing that I may find access to the rheostat.
So this is where I ask if anyone has gotten to this point and been successful?

Eric Maclean:
Don
In your picture at the lower right corner is the blower motor resistor block if you remove it you will find
That there is a piece that looks like a diode on the side with the resistor coils.
This is actually a thermal fuse
To confirm the thermal fuse is blown simply running a jumper wire across it should restore all the fan speeds.
There should be a number on the blower resistor itself check it against this one Ford # D8BH-19A706-AB  found in a 1980 Ford F100 with A/C
This  crosses to a Standard Motor Products #RU-439

https://www.ebay.ca/itm/392482056347

You are likely correct about the heater hoses being clamped because these systems don't use a blend door the air is routed through both the A/C evaporator and the heater core and the temperature is controlled by the heater control valve ( flow) unfortunately these control valve are notorious for not closing completely and the small amount of flow that gets by can degrade the A/C cooling ability hence the clamp to improve the A/C operation

Hope this helps
Eric

Steve Huber Co-Admin:
Don,
I had a similar issue with the hot antifreeze fluid being routed through the dash HVAC system degrading the A/C system output. I installed a manual shutoff valve in the heater line. However, having to guess or stop to open it when I wanted heat or to defog the windshield was a real PIA. If i were to do it again I'd install an electric valve and run it to a switch in in cockpit. Here's an example. https://www.electricsolenoidvalves.com/1-2-12v-dc-electric-brass-solenoid-valve/?gad_source=1&gclid=Cj0KCQjwgrO4BhC2ARIsAKQ7zUlKZfpLPa3eXLu8HNGtrP77WoN1OiGTQD0f_TGu9TLxvJfIXF9qAx4aAhLLEALw_wcB
Steve

Don Forsyth:
Eric and Steve, thank you both. This is great information.
I have to ask though, did you access everything from the top or did you come up underneath between the firewall and front cap. I am on my  knees with all kinds of things poking into me to try and reach the pliers and I am about 4 inch short of reaching them. I am 6 foot and 180 lbs so I should be able to skinny up in there. I don't know that there is enough room to get two hands in there or not.

Steve Huber Co-Admin:
Don,
I had a slide out geni so access was easy. On my previous coaches I had a skinny tech at the service center I used. :)
Steve

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