2005 e250 blower motor-what else can I try?

[B1200]

Hi All,
I`m hoping someone here might have insight into my problem.
So here it is: the blower motor in my van only works intermittently. Initially the symptoms seemed to indicate a faulty blower switch, it would stop working or only worked on high.
So I changed the switch but that did not fix the problem. Then I took it to a mechanic I use and he changed the master ac/heater control switch, which apparently is connected to the blower switch. It worked when he test drove it but soon after I got it back I left to go camping and the problem returned. But on that trip I did noticed a pattern to the motor working/ not working. I noticed that when I let off the accelerator or step on the brake, while the blower is not working, it will start working again. But then it will stop again after a few seconds or a few minutes. Sounds like a short right?
Well I've since had it back to the mechanic and had the following done with no luck; changed the blower resistor and motor, tested the power wires for a short, (lights connected to power wires remained lit when blower quit), cleaned and repositioned the ground wires, bought all new connectors and ran new wires to bypass a possible short buried in the wiring harness, and then ran out of things to try.
It seems to me that basically the whole system has been replaced so not sure what to try next. So if anyone has an idea I would really appreciate it.
Thanks a lot

[1der]

It is a frustrating path, for sure.

Just to help complete the picture:
Passenger or Cargo?
Rear A/C and heat? Factory installed or ??

Blower motor - when working and not working, does it change with master selector knob for floor, defrost, A/C, etc?

[B1200]

Hi 1der,
Replied last night but it appears it didn't post.
My van started life as a Pleasureway Camper van and then a few years before I got it, it was converted to 4x4.
The ac/heater is the original unit that came from Ford. There is no connection to the house heater (which was removed by previous owner).
The directional vents seem to work when the blower is also working but I didn't specifically test for that. I did try adjusting the master controller in an effort to get the blower going again but to no avail.
Hope that helps, as I think I am out of ideas.
Thanks

[BrianW]

As an aside, for some reason PleasureWay ordered their Traverse base vans with the rear aux AC/heat option and then deleted the rear parts, leaving only the dash aux blower switch. So the previous owner didn’t remove it; PleasureWay did (I owned a 2002 Traverse).

[BrianW]

Also, read up on the common HVAC “blend door” issues with e-vans. Your description doesn’t exactly sound like this issue, but it could be. For example: https://www.sportsmobileforum.com/fo...air-18091.html

[B1200]

Hi Brian,
I don't see any indication that the front controller on this van, which is indeed a Traverse, controlled the rear ac/heater. The previous owner told me they removed the rear heater, which was located under the rear bench, because they felt it was too loud when it switched on. Also, my Pleasureway owners manual indicates it came with a Suburban brand heater in that location and the van still has the propane supply line which connects to the propane tank underneath the van.
Still, I can't say that there isn't some issue that involves the house heater but I don't really see how. And it all worked fine for the first 3yrs I've owned the van and just started acting up this summer during a trip to the desert.

[BrianW]

^^ Ah I thought you were talking about the OEM rear HVAC system. Does your dash have a second blower control knob like shown in the pic below? That’s what I was talking about. If so then the van originally also has the OEM system.

[hogasm]

Look at relay under battery box

[B1200]

BrianW, I don't have that setup in this van. I previously owned a 2003 e350 EB that had the rear ac/heater with a similar controller on the dash but my e250 doesn't have that.

To: hogasm, which battery-starter or house. I would assume starter battery? And what relay would it be. I mean what is it for? That is something I haven't had checked but I'd like to understand what it is and how it relates to the blower.

[hogasm]

It’s under the battery box in front of ac box, passenger fender