heater/ac controls not working, sometimes

[BoB393]

Hi all, It's winter and no defroster S@C$S!

I have an 03 limited and the heater controls are working intermittently. Mostly not working. Sometimes if I'm lucky I can hit the dash above the radio and it will start to work, for a while and than it stops again. Sometimes a pot hole will do it also. I don't know if it's the control module, a bad connection, or an bad fan motor. Anyone have any thoughts on it. It seems to be a common problem but I just don't know where to start. Thanks.

[imidazol97]

Originally Posted by BoB393

Hi all, It's winter and no defroster S@C$S!

I have an 03 limited and the heater controls are working intermittently. Mostly not working. Sometimes if I'm lucky I can hit the dash above the radio and it will start to work, for a while and than it stops again. Sometimes a pot hole will do it also. I don't know if it's the control module, a bad connection, or an bad fan motor.

--
My guess would be that it's the motor itself. The brushes on my 03 wore down and one of the brushes was sticking in it's channel. As it wore, it wouldn't touch to make contact. A little vibration from a bump would start it--OR I could tap the bottom of the motor with the toe of my shoe and that would start it.

People also have reported bad or burned contacts in the connector for the motor to the wiring on the HVAC. So you can check both. The round housing is right above the passenger's left shoe. A little time lying on the seat or floor will let you test it when you find it's not working. There is a plastic shield under the dash to remove carefully. It has an air flow channel through it.

I replaced with a blower motor from Autozone because they were the only store in the area that stocked them, and only two of the 8 or so stores had it in stock. It vibrates slightly on highest speeds, so I wondered if another brand related to original equipment might have worked better.

The blower motor has three screws holding it. There is a rubber air tube to the motor from the air ducts to cool the armature. A little tight, but removable by the DIYer.

Good luck troubleshooting.

[BoB393]

Thank you,
This gives me a place to start. I'll tap the motor in the morning and see what happens

[imidazol97]

Originally Posted by BoB393

Thank you,
This gives me a place to start. I'll tap the motor in the morning and see what happens

If the problem is the same as mine with sticking contacts on the commutator, the wear may have become larger and the sticking won't let it vibrate and make contact. That's what mine did and it took more to get it working. So I replaced it after a couple months of kicking.

[BoB393]

Happy New Year everyone!

You guys called it!

All I did was tap it with my toe and it started right up!

I'm glad it's the motor that costs $50 and is held in with three screws and not the control unit hat costs $450 and you have to pull the dash apart to install.

Great save, thanks