Blower fan qustion

99% of the time, if the fan works on any speed, it will work just fine on high speed too. I think your blower is fine. High speed draws the most current, (amps). Any time anything electrical gets hot, it is from a bad connection resulting in too much resistance, the resistance creates heat. I suspect the problem is the terminals your breaker plugs into are spread resulting in a weak connection. The connection is too weak to allow that much current to pass through. This is what causes the heat. Pull out that breaker and check those terminal pins for being spread and likely now discolored too.

 

Not sure about that particular truck but most fan speeds are usually controlled by a resistor block. Each speed is stepped down by a resistor.

They are usually mounted right beside the blower motor. You should be able to follow the wires out of the blower motor will go right to it. I'll look further and see if yours has one.

 

I found this, maybe it will help. Read post# 7

http://www.dieseltruckresource.com/dev/international-truck-experts-t207948.html



The blower resistors look like this. This is a Peterbilt/ KW. I didn't find one for an Int'l. The coiled wires are the resistors of sort. Actually it's metal that current doesn't flow good so the voltage gets knocked down.

 

I didn't think about yours being under the seat. If it had a resistor I doubt it would be in an open area. It's usually hidden under the dash or outside on the firewall for blower motor that are mounted that way. I did read something about a resistor under the glove box area. But read that post that guy's problem sounds very similar to yours.

 

Hello, all of you gear-heads. I have the volvo, I don't know if that would make the diff.

However:

Here is my situation, I do not want to waste money for things that are not broken, my cab blower motor stopped working.


Here is what I've done: I've pulled the blower motor out and connected it to the 12v battery, directly, and it worked fine. So, I'm thinking that my blower motor is in working condition. Correct?

Now, I'm not to electrically savvy, so, here is what else I've done: there are 3 plugs on the blower motor assembly. One plug, two wires, connects to the motor itself. Another plug, bunch of wires, connects to what looks like the heat exchanger - shaped like half moon, and bolts to the motor housing with two torx screws. Third plug, looks like it connects to the "thermometer"?

Next, I've put the volt meter on the plug that connects to the motor, while the plug is connected to the motor. With all of the plugs connected my reading was zero Volts. If I'll unplug the motor plug, and still keep my multimeter leads on that plug, the reading will jump to 12V, depends on the speed that is on the fan setting. Voltage would fluctuate if I'll change the fan speed setting. If I'll plug the plug, from the wiring harness, back into the motor, the voltage would drop to zero volts. Also, if I'll unplug the plug with multiple wires, from the half moon shaped heat exchanger looking thingy, and keep the motor plug unplugged then the reading will drop from 12v to zero V. If I'll plug that plug, from the half moon looking thingy, back in, and keep to motor plug unplugged, then the voltage reading on the motor plug will jump up to 12 or so volts, dependent on the fan speed setting.

By the way, the blower fan and climate control in the bunk work fine. The above issue is in the CAB portion of the truck.


ANY IDEAS WHAT IS WRONG OR WHAT I NEED TO REPLACE?????

 

Make a new thread in the Volvo specific forum, this one is for Internationals. Maybe a forum staff member can move your post for you so the Volvo guys can find it!