I left truck in the cold last winter without turning it on.

Now when I turn heater on it dont start. I replaced the
fuse and when I turned it on, nothing. Fuse blown again.
Seems fuse gets blown immediately.

Could it be the Blower Switch Relay? If so where is it located.
I read its under the hood on passenger firewall close to the fan motor
but I dont see anything there that resembles the pic Rockauto shows for it.

Or could it be something else?

 

Manual HVAC, or automatic climate control?

On manual HVAC systems, the relay is only used for the high speed on the blower, (the lower speeds go through the resistor). Not likely the relay shorted out. Unplug the blower motor connector and see if the fuse blows when you turn the blower on, (could be the blower motor seized up from not being used).

 

Dont know if its manual or automatic. Its 2000 Blazer LS model.

I assume the blower motor connector is by the motor. Right? I'll try that and see if the fuse blows. (gotta buy new fuses. used up the spare i had).

Will try tomorrow morning.

thanks

 

This is a manual HVAC control:


Does yours look like this, or does it have temperature degree markings?

The blower connector plugs into the blower motor, next to the passenger side hood hinge, under the hood.

 

Yup. Looks just like that. Manual then!

After I disconnect blower and start it again, what does it mean
if fuse blows or not?

 

With the blower disconnected, turn the ignition on, select AC, turn the blower switch on: If the fuse does not blow, the motor is shorted out or seized up. If the fuse still blows, it's not the blower time to look for a short circuit somewhere.

 

I disconnected blower, turned ignition on, selcted AC, and turned blower to 2 and the FUSE BLEW. (short circuit then, right)

My friend then ran some wires fr Battery to blower plugin and blower did not spin. (he says the blower motor is dead. huh?)

 

If it happened in that exact order, there is a short in the wiring.


If you had a good connection, both positive and negative at the blower motor, and the motor did not run, the motor is faulty.

It's not impossible to have two problems It's possible that the blower motor started drawing too much current, melted a wire somewhere so it's touching ground. Once the feed wire touches ground, the motor will not work.

 

Yea, sounds very logical. . . Thanks for helping me out. Tomorrow, if possible,
we are gonna look at it some more and verify that we did in fact have a good
connection. And look for a short.

 

After connecting and disconnecting motor and resistor plugins its NO LONGER blowing the fuse.

I decided am going to replace both. However when I contacted Rockauto
they said some blower motors have a vent tube as part of the motor.
And I dont know if mine requires it since it is still installed and I cant see it.

They dont have the software to tell from the VIN #.

I saw that VDO part # PM137 is tagged a favorite on their website. This is the one without the vent.
The Four Seasons part # 75783 has the vent tube.

Should I just order the VDO part #?..........Never Mind. My friend cut the covering. It's the NO Vent.