'92 Dodge Ram Van B250 with intermitant blower. With the fan switch on in any position, the blower will cycle on and off.

2 things I noticed:
1 - some amount of "squeal" from the vent when the fan is running
2 - it seems like the fan runs less when I accelerate or when at higher speeds (70 to 80 mph)

My gut feel is that it's the motor but if there were a simple way to test the switch, that might be easier and less expensive if it in fact were the switch.

thanks in advance

 

It does sound like the motor, but the switch is a simple OFF-ON-ON-ON switch whch can be checked with a VOM. The wires go to the Heater Resistor located on the pasenger firewall. generaly if that fails though you loose a single speed for the blower. If the resistor iscracked or loose that may make it intermitant.
Since the resistor is the speed controller, you can also hotwire the fan as a test by giving it straight 12v from the battery, though check with a meter, since one of the fan wires is ground and you dont want to use that one.
Some DC motors don't mind running in reverse, I dont know if the fan blower is one of them.

 

I was wondering what that resistor was for. With all this new knowledge I'm sure I can figure this thing out although as we all know "knowledge can be a dangerous thing in the hands of a shade tree mechanic".

thanks,
mike

 

Just replaced the blower moter. I have a 1993 B250 and I had to describe the "flange" to the guy at www.ackits.com. But they got the right part. The challeng is getting to all of the little screws on the top under the AC unit flange. You will test your socket wrench adaptor, elbow, extension collection.

Good luck replacing this. Now that I know how to do it, assembly was a beeze.

I knew my fan was dying when I would hear clicks some cold mornings. I then threw it into high and then OK. this lasted 2 years.

One morning, click, click clikclik CLANK CLANK SPLITT.

No heat.

If it sounds mechanical, and you can hear this though the vent by the passenger's feet, I would say that the blower is about to kick it. $62.

Of course your situation is different. 4 out 6 cars I had that hit 100,000 miles had their fan go out around 80,000 to 100,000 miles.

 

Thanks zenman. After your description of the removal process I will definitely check the switch and resistor first.
I have a fairly good selection of adaptors and swivels for my sockets but this looks like an oportunity to more tools!

 

The best tools I've seen for taking the blower motor off are closed end wrenches that have ratcheting centers. All the slimness of a wrench,and the joy of a ratchet. of course i havnt been able to find ones I can afford either. Oh well.. Think the blower is a pain? Try changing the heater core sometime.

 

I bought a factory repair manual as well as the Haynes book and was readingthem last night. According to them, I actually have 2 choices to remove the fan motor:

1) remove the 3 nuts that hold the fan to the fan mounting plate
2) revove the 4 bolts that hold the fan mounting plate to the heater "box"

My van is a '92 318 w/AC.......... based on what I've read above I guess I just got lucky with this one...

I'm always looking for excuses to buy tools so if I come across any reasonably priced reasonable quality closed end rachet wrenches I'll let you know.

 

That's what I thought after reading the service manual. The 4 bolts turned into 6 to get the fan out of there and two of them are impossible to see from any angle. One things I noticed is that I couldn't get the fan out of the engine compartment until I seperated the motor from the fins. Of course, you have to take out the engine fan shroud first.

Good luck.