Hi Gang,
Having perused the board for messages about blower motor troubles, I thought I'd add my experiences with the bugger. The truck is a '96 with 160k on the odo.
1st: intermittent blower; turned out to be a loose connection at the resistor module for the blower speed control, which is located just left of the lower motor. A shot of contact cleaner and a good push on the connector solved that problem.
2nd: blower speed varying with acceleration/deceleration, and sometimes won't start turning at all.
Removed the motor, pulled the fan blade off the shaft. Noted a pile of brown/black dust collected inside the bottom of the motor housing, looking though the vent hole where the rubber tube was connected prior to removal. Held the motor casing securely, I connected the motor to a charged battery. . works OK, but kind of slow and seems to be struggling. Noted bottom end of motor casing becoming hot from friction. Inspection via the vent hole showed the bearing covered in the dust/gunk from the armature brushes wearing out. I shot in some contact cleaner on the bearing, and hit the brush/armature area with the cleaner as well. Then I lubed the bearing with spray silicon lube and re-connected the motor to the battery. . it ran much easier and the bearing end didn't get hot; noticeably warm, but not hot.
I think what is happening is that as the motor brushes wear, they slowly disintegrate and the dust fall out settles in the bearing area at the bottom of the motor casing, causing extra friction in the bearing, thus the heat.
The blower speed variance with acceleration (slower blower) and deceleration (faster blower) is due to the brushes being almost worn out. The motor appears to be sealed, but I'm sure a determined person could open the case and possibly replace the brushes. Hey, if the motor dies you got nothing to loose by trying. I'll delay that process until mine craps out totally; a replacement costs anywhere from $40 (reman) to $100 (new).
Having perused the board for messages about blower motor troubles, I thought I'd add my experiences with the bugger. The truck is a '96 with 160k on the odo.
1st: intermittent blower; turned out to be a loose connection at the resistor module for the blower speed control, which is located just left of the lower motor. A shot of contact cleaner and a good push on the connector solved that problem.
2nd: blower speed varying with acceleration/deceleration, and sometimes won't start turning at all.
Removed the motor, pulled the fan blade off the shaft. Noted a pile of brown/black dust collected inside the bottom of the motor housing, looking though the vent hole where the rubber tube was connected prior to removal. Held the motor casing securely, I connected the motor to a charged battery. . works OK, but kind of slow and seems to be struggling. Noted bottom end of motor casing becoming hot from friction. Inspection via the vent hole showed the bearing covered in the dust/gunk from the armature brushes wearing out. I shot in some contact cleaner on the bearing, and hit the brush/armature area with the cleaner as well. Then I lubed the bearing with spray silicon lube and re-connected the motor to the battery. . it ran much easier and the bearing end didn't get hot; noticeably warm, but not hot.
I think what is happening is that as the motor brushes wear, they slowly disintegrate and the dust fall out settles in the bearing area at the bottom of the motor casing, causing extra friction in the bearing, thus the heat.
The blower speed variance with acceleration (slower blower) and deceleration (faster blower) is due to the brushes being almost worn out. The motor appears to be sealed, but I'm sure a determined person could open the case and possibly replace the brushes. Hey, if the motor dies you got nothing to loose by trying. I'll delay that process until mine craps out totally; a replacement costs anywhere from $40 (reman) to $100 (new).