I just finished putting the sheet metal covers back on the Atwood unit up front on the pass side. With the covers off the heater vents have a very strong air flow. With the covers back on the air flow is just noticeable with the blower switch on high. I did back blow the heater core and the A/C core while I had the covers off, so I know they are clean.
I wonder if the air intakes under the dash might be restricting the air intake?
Anyone encounter something like this?
Gonna check tomorrow.
If there is no vacuum to the controls the doors will not operate correctly to allow the air to flow. Check to make sure the vacuum pump is working
Thank you Ron. I woke up this morning and while laying in bed the same thing occurred to me. Nice to have confirmation to my analysis. I have the manual right here and am going to study it before going out to the coach.
Well, the little Brailford vacuum pump wasn't kicking in so I had no vacuum to the control and hence to the three door actuators. The DW went on the Internet to Brailford----Big sticker shock!! The pump assembly (that you could hide between your cupped hands) goes for around $163.00!! Plus shipping. I guess they don't think they have you ripped off enough with just the price of the pump.
I took the pump apart, down to the little eccentric shaft and bearing. I put a couple drops of sewing machine oil on the bearing, ran the pump for about 1/2 hour, reinstalled the assembly in the coach and now the control doors move!! SWEET.
Next is to try to find a new pump for a reasonable price.
While checking things out I noticed the duct under the dash on the pass side looked like it was partially blocked when I shined a flashlight up inside the vent. I took the vent off, found about 16" of ducting where 4" would suffice. The outlet on the Atwood box was pointing about 3" below the cutout opening in the plywood. After dismantling the lower dash I cut the opening lower and remounted the ductwork and vent cover. Guess what? Air now comes out that heater vent. Also, a plug that was supposed to block a unused duct opening on the Atwood box was laying far over toward the driver's side. So heat was pouring out behind the plywood and carpet panel instead of out the ducts. Kept things nice and warm up IN the dash. Kind of explains why we weren't getting much heat in the front.
Thanks for the post....ours too barely blows out any air, cold or hot. This is one of the projects that has to be done before our next winter trip to FL.
Jeff