The customer called and said that their 1998 Chevrolet Astro van only had the high blower working but by the time it showed up a couple of days later the blower had stopped altogether. Simple test for no blower on an older high mileage vehicle, turn the key on, set the blower to high and bump the motor case with the handle of a hammer. If the blower comes on the motor is faulty or there is a loose connection at the blower motor itself. The blower came on but only worked on high and the connections were clean and tight, so the motor is faulty but there are other problems with the lower speeds..
To remove and replace the motor is pretty simple. Remove the coolant and washer fluid tanks. Unplug the motor, remove the mounting screws and pull the motor from the vehicle. It takes a little rotating and twisting of the motor assembly to remove it. To install simply reverse.
Next, I turned my attention to the lower blower speeds. The blower resistor and relay unit is right there so I removed the positive assurance clip and unplugged the resistor. The connector was burnt and had to be replaced along with the resistor. Whenever there is heat damage at a connector both the connector and the component it attaches to have to be replaced at the same time for a lasting repair.
I spliced in the new connector and you will notice I staggered the joints for a neater repair.
The blower resistor design has been updated and as a result I had to modify the blower case to accommodate the new resistor.
There was a paper template supplied with the resistor and I cut it out and placed it over the hole to mark the new outline.
It really did not work to well so I just cut and rechecked until the new resistor would slide in the hole and mount squarely on the mounting bosses. I used a rotary cutting tool and a file to open the hole up. I also used a shop vacuum and an air hose through both the blower motor opening and the resistor opening to remove all of the cutting debris.
After that I just reassembled all of the pieces and checked for proper operation.
A new blower motor, blower resistor and blower resistor repair harness and the job was done.
These vans have inherent problems that cause the terminals to burn out. The main problem is at the red wire, terminal “A” for the high blower speed. As the vans age they develop air leaks throughout the vehicle. This causes to operator to use the blower in high speed at all times to gain comfort in the van. By doing this the terminals overheat and fail. There are two ways to overcome this. 1. Make sure the van is properly sealed and the a/c system is in tip top shape. This will reduce the need to operate the blower at the highest settings. 2. Every 10-30 minutes make changes to the blower speed to help prevent single terminal overheating.
Another big problem is dirt build up on the evaporator core fins. This forces the operator to again use the blower on the highest settings. It also increases the blower motor amperage draw. Both will result in overheated blower resistor terminals.
If you are lucky enough to have rear a/c on your van, be sure to use it, to take some load off of the front blower system.