QuestionI have a 99 Plymouth Grand Voyager, 3.8L engine, and it has a blower problem.
The blower will make a low pitch whining sound, louder than the regular fan noise, but no too loud. The fan speed will slow down, without my adjusting the speed knob. Sometimes, it will just quit blowing, but I can turn the knob after a while, and it will start again. Sometimes, after being parked, and starting it up again, the fan won't blow at all, then after 5 or ten minutes, I can turn the fan knob, and it will blow fine for a while. Sometimes a long while (hours), sometimes shorter (10-15 minutes.
I've read a lot of the answers, and it sounds like either a blower motor resistor, or a relay problem. Can I pull those parts and have them checked to see if they are OK, or do I just have to buy new ones and try them out?
Thanks!
AnswerHi Scott,
The blower and its circuit are fairly simple, but it is not certain why you have the symptoms you describe. For current to pass throught the motor it has to flow through fuse 21 in the box under the hood (check for whether the wire in the fuse may have a subtle crack which can open spontaneously and then reconnect when cool), to the points of the blower relay (fifth from the front in that same box (points could be corroded leading to variable flow of current), then to the motor and finally to the resistor block with 5 possible paths involving any where from none to 4 resistors (usually this a go/no go sort item, rather than an intermittent), and finally the control switch (which might be flaky at certain speed settings), and then to ground (connector wire screwed to the chassis under the dash behind the control panel (this, and the rear blower if equipped), are the only items on this ground point so you would want to check it as well.
The variable sound of the motor makes me suspect the motor itself, possible could the fan rotor be rubbing on the housing? Or the brushes of the motor could be going bad. That unit is accessible under the AC/heater housing on the passenger-side of the unit. So that might be the place to start to see if it may just be binding up. Usually the other parts of the system will affect the current flow/or none rather than change the sound. The wires from the 10-wire plug on the back of the control go to the resistor block itself which is located in the air intake and is accessed from the engine compartment on the fire wall behind one of the openings near the passenger side strut tower. You can by-pass the control switch and resistor block and apply 12V
You can jump 12V to the motor on its 2-wire plug nearby and see if it still behaves the same way in which case that would tell you it is the motor/blower wheel that is the problem. If that seems ok then look at the control switch and relay points. Of course it is easy to check the fuses so maybe begin there.
Roland
