When it's cold outside (below 45) the blower motor will not turn on in heat or A/C mode but as soon as it warms up enough to check it the dam thing works. So I will need to diagnose it while it's cold. Anybody ever had or heard of this problem or any ideas on where to start looking?
Engine Temp doesn't seem to affect it. The engine warms up by time I get to work but the fan still doesn't come on but it works everytime when I go home in the afternoon.

 

That's weird. Give it till everybody gets off work and can log in...somebody will have an answer!

Joe

 

That sums up my week. Wierd.. I installed a new remote PLC last week and all this week it's been locking up without any errors. Maybe it doesn't like the cold too.

Hopefully this Bump^^ wil gather some insite on this problem from others who know where I should start looking.

 

Bumpity Bump!

Anyone have a resolve for this? I too have been tearing my hair out over the same weirdness.

Of course my local stealership is useless.

Thanks

 

If the resistor is cracked, temperature could cause warping that could open the circuit or close it. Pull the blower resistor, and ohm each of the circuits (three or more plugs, common ground) when in is cold. Also look for cracks in the stabilizing structure on the coils.
This is the only thing I could guess.

 

Even if the resistor is bad it should still work on high speed.

 

True. High speed is straight through, with no resistor. Does high speed work?

 

critter is right, if the fan is on high, the blower motor resistor is completely bypassed. I would be thinking along the lines of an intermittent blower motor relay myself.