Blower motor Problem

[Ruffiano]

So my blower motor on the CQ is giving me a hard time. I swapped it to a B4 manual set up and it was working shortly after the swap. Over the course of time and with many trips behind the dashboard (for other reasons)one of the connections to the blower motor become un plugged. I didn't really care since it was almost summer and the car doesn't have A/C so no biggie. Now that it is cold I made an effort and removed the glove box and sure enough there was my power to the blower motor sitting unplugged. Plugged it in and reinstalled my glove box with a smug look on my face. Next morning rolls around and I got NOTHING! So now I'm confused. I checked fuses which were all fine. I removed the glove box again, everything was plugged in, i removed the ground wire and connected the blower motor directly to ground and turned the ignition to the on position and sure enough I get blower! It can't be controlled by the knobs but it is working, it doesn't seem to be at max speed but either the 2nd or 3rd position.

After lots of searching on the forums I found that the resister pack is a common failure, however the failure normally has a different set of problems, if it is the resister pack the blower motor still works when you turn the switch, but only works when in the 4th position. I'm leaning more towards a problem with the actual switch/knobs. Any other insight on this? Thanks!

[Ruffiano]

Nobody use their blower motor?

[johne]

So my blower motor on the CQ is giving me a hard time. I swapped it to a B4 manual set up and it was working shortly after the swap. Over the course of time and with many trips behind the dashboard (for other reasons)one of the connections to the blower motor become un plugged. I didn't really care since it was almost summer and the car doesn't have A/C so no biggie. Now that it is cold I made an effort and removed the glove box and sure enough there was my power to the blower motor sitting unplugged. Plugged it in and reinstalled my glove box with a smug look on my face. Next morning rolls around and I got NOTHING! So now I'm confused. I checked fuses which were all fine. I removed the glove box again, everything was plugged in, i removed the ground wire and connected the blower motor directly to ground and turned the ignition to the on position and sure enough I get blower! It can't be controlled by the knobs but it is working, it doesn't seem to be at max speed but either the 2nd or 3rd position.

After lots of searching on the forums I found that the resister pack is a common failure, however the failure normally has a different set of problems, if it is the resister pack the blower motor still works when you turn the switch, but only works when in the 4th position. I'm leaning more towards a problem with the actual switch/knobs. Any other insight on this? Thanks!

As you've worked out the blower motor has 12 volts connected to it all the time once the ignition switch is on. The speed control (resistor pack) and the fan selection switch are both in the ground connection to the blower motor. S2central.net has the wiring diagram. As you've said in the max speed position the resistor pack isn't part of the circuit, the knob connects the motor straight to ground but the wiring still all goes through the resistor pack so you could have a bad connection there, especially as the current draw is high.

You imply that the motor doesn't run at full speed if you ground it directly. If correct, that's not right. Is the motor partailly siezed and in need of cleaning/lubrication? A partially or fully siezed motor is the cause of the resistor pack failing. In fact it isn't the resistor pack that fails but the silver thermal fuse that runs over the top of the resistor pack. That thermal fuse is easy to replace but as you've said, even if it's failed, you should still be able to get full speed.

Suggest you also check that when you ground the motor directly you really do have 12 volts - or 14 volts with the engine running - at the motor. You may be loosing volts in the supply cable to the motor due to a poor connection.

My best guess is that a partly siezed motor has drawn excessive current thats fried one of the connectors in the circuit.

John

[Ruffiano]

thanks, found out it had a bad connection at the switch.