'03 EB Front Blower Motor High Speed Only

[stilbo]

I've repaired a few Explorers and F150s with a "high speed only" blower motor problem. It's always been the resistor pack. But on manual control HVAC systems.
I just bought an '03 Expedition EB with auto climate control and the front HVAC fan will only run at maximum speed. I've checked Advance Auto and O'Reilly's and they offer a resistor pack with a big honkin heat sink and transistor pack as the resistor replacement all for $96.00.
If I were replacing a $23.00 resistor I'd just roll the dice and buy, install and hope for the best but at nearly $100.00 I'd like to be a bit more certain about my diagnosis.
So....
My problem is the resistor pack with big heat sink on the front fan housing, right?
Thanks,
Ron S

 

[stilbo]

Update... Found the "controller" aka resistor for $57 on Amazon. Still want to be sure before I pop the cash.

 

[rock3ralex]

If you can find the actual resistor value or you can the parts on an electronics site and replace it for no more than a few bucks

Sent from my HTC6435LVW using Tapatalk 2

 

[ohillny]

Having the same problem

I have a 2000 xlt 5.4 that will only blow air on the highest setting. COuld this also be the resistor or do I have a dying blower?

 

[stamp11127]

Until the defective part has been found, it could be any of them. Invest is a DVM if you don't have one and we will tell you how to check the parts.

 

[ELVATO]

My bet would be the resistor pack.

 

[ohillny]

Yeah what is "dvm"? and if it is a resistor pack are these under the dash and is it a single unit that can be replace?

 

[hwy73]

The Electronic Automatic Temperature Control (EATC) uses a Blower Control Module (BCM) to control the fan speed as opposed to the resistor coils used on the manual systems. This provides the many fan speeds controlled by the thumbwheel on the control panel as opposed to the four speeds provided by the rotary switch on the manual versions. The module is mounted in the hvac box, in the airstream, with a large heatsink and circuit board inside, and the electrical connectors on the outside. These modules have been troublesome on the "panther" cars (Crown Vic/Grand Marquis), causing intermittent blower operation. The cause is incomplete solder connections on the circuit board. Tapping on the module with the butt-end of a screwdriver will sometimes temporarily restore operation. Replacement "new" modules wil be affected the same way as it is a manufacturing defect. The permanent fix is to resolder the wire connection points on the circuit board. You will have to find where the module is located on the HVAC box in the Expedition. On the panther cars, it is on the A/C plenum under the hood on the firewall. The photo of the circuit board shows the burned solder joint on one of the large pins. When these are acting up and arcing, you will actually get a burning electrical smell from the vents inside the vehicle.