PSD E-van not defrosting.

[curtis73]

So the cold and the rain (stupid Sandy) have revealed a weakness in my E-van that hadn't been there before. The defroster always worked well until now.

I verified that the A/C compressor is coming on. Its not cycling abnormally as if there were a low charge but I haven't verified pressures. The air is blowing out of the defrost vents and its plenty hot, there just isn't much of it.

Just thought I'd ask if there was a common failure point to this. I can dig in and start diagnosing fan speeds, dirty heater cores, etc... but that isn't exactly an easy thing to check on an E-van. I thought if there were a common failure I could start there first.

[jamiesgarage]

is it working on all speeds?

TSB
11-11-21
FORD: 1997-2012 E-Series


ISSUE:
Some 1997-2012 E-Series vehicles may experience a blower motor that is inoperative, operates incorrectly, or that only functions on one speed.

ACTION:
Follow the Service Procedure steps to correct the concern.

SERVICE PROCEDURE

Replace the blower motor switch following Workshop Manual (WSM), Section 412.
Replace the blower motor switch pigtail following Wiring Diagram procedures for proper wiring repair.
If the concern is still present, follow normal diagnostics. Refer to WSM, Section 412-00.

[curtis73]

Yes, fan is working on all speeds... or at least it changes speeds with each setting of the switch. It seems awfully quiet and doesn't move much air.

After seeing that TSB though I will do two things; test voltage before and after the switch, and power probe the motor to see if it works better than going through the switch. I'll also see how much amperage the motor is drawing.