Windshield defroster question
I have an older 1987 Class A Gulfstream motorhome that I have restored over the last 3 years. It was in excellent condition to begin with.
There is one nagging problem that I cannot figure out, and that is how does the defroster work?
I cannot divert air to just the defroster like a car, where all the air from the blower comes out the defroster vents. I have examined all of the duct work and have had the dash apart. There doesn't seem to be a diverter door anywhere or a vacuum motor to actuate such a door. Manually closing all of the dash vents does nothing. Is there a vacuum motor inside the plenum somewhere?
The original control head was junk and I replaced it with custom rocker switches that open/close individual vacuum switches for MAX, A/C, and HEAT, and it works great. Getting air to blast out of the defroster remains a setback. There are no leaks at the vents that would allow air to escape under the dash. I'm stumped!
If anyone can find a link to the HVAC vacuum diagram for this would certainly help. There has to be a 4th vacuum motor somewhere.
There is one nagging problem that I cannot figure out, and that is how does the defroster work?
I cannot divert air to just the defroster like a car, where all the air from the blower comes out the defroster vents. I have examined all of the duct work and have had the dash apart. There doesn't seem to be a diverter door anywhere or a vacuum motor to actuate such a door. Manually closing all of the dash vents does nothing. Is there a vacuum motor inside the plenum somewhere?
The original control head was junk and I replaced it with custom rocker switches that open/close individual vacuum switches for MAX, A/C, and HEAT, and it works great. Getting air to blast out of the defroster remains a setback. There are no leaks at the vents that would allow air to escape under the dash. I'm stumped!
If anyone can find a link to the HVAC vacuum diagram for this would certainly help. There has to be a 4th vacuum motor somewhere.
