I got in my 2000 Expy yesterday after a 4 day trip and it wouldn't start. I got a jump and got it home. When I turned it off I noticed the blower motor was still running. Now I know what ran the battery down, but what is allowing the blower motor to run with the key off or out for that matter. My guess would be the ignition switch. Any ideas????

 

Did it rain? I think this might be a symptom of the GEM getting wet.

 

Yep. It rained while it was parked outside. What is the GEM and where is it located?

 

The GEM is generic electrical module. It controls many of the vehicle's electrical components (although I don't think fan is one of them) and is located behind the fuse panel inside the truck.

 

I did a search and it seems that the GEM does control the blower motor. Now does anyone have a detailed description of how to replace it and does it have to be reprogrammed?

 

The generic electronic module (GEM) constantly monitors its subsystems for concerns. If a concern is found in one of the subsystems, the GEM will record the concern in the form of a diagnostic trouble code (DTC).

The ignition switch position is very important to the GEM function. Often times, erratic or unexpected GEM function can be traced to problems with these GEM inputs.

The GEM controls the following features:

l Wipers/washers (front/rear).

l Warning chimes.

l Battery saver.

l Illuminated entry and courtesy lamps.

l Driver power window.

l Accessory delay.

l 4-wheel drive.

l Heated backlite/mirror.


GEM Feature Matrix
Safety Belt Warning Indicator(*)
Key-In-Ignition Warning Indicator(**)
Headlamp-On Warning Indicator (**)
Front Windshield Wiper/Washer Control
Interior Courtesy Lamp Control
Battery Saver
One-Touch Down Window
Delayed Accessory
Door Ajar Warning Indication (*)
4-Wheel Drive (A4WD)
Rear Wiper/Washer Control
Heated Backlite/Mirror
Low Washer Fluid Warning Indication (*)
Running Board Lamp Control
(*) - This feature provides an audible warning and an indicator lamp.
(**) - This feature provides an audible warning.

The old GEM must have its information uploaded to a scan tool then said info must be downloaded to new GEM.