MY BLOWER MOTOR SLOWS DOWN AND SPEEDS UUP ON ITS OWN

CHECK UNDER THE DASH ON THE PASSENGER SIDE AND FIND THE FAN MOTOR, THERE SHOULD BE A

Blower Motor Resistor WITH PLUG ON IT, IT SHOULD BE HELD ON WITH 2 SCREWS. THIS IS THE SWITCH THAT CONTROLS FAN SPEED.

may be motor on way out ,,,,, the resistor for the system usually allows full blower power when set to top speed,,,,

you may have had something fall down into the defrost vent and it has worked its way down and is blocking the air flow thats trying to come out the vents,near the blower motor.also does it sound like the blower motor is spinning on high speed or at a lower speed,you could have a slow turning blower motor.

Being a Plymouth,I would look at the fan switch in the dash,bet it doesn't look ok !!

You need a new blower resistor by the sounds of things. When you select the three lower speed settings, the current supplied to power up the blower motor goes through the resistor, to slow the speed of the blower motor down. When the high speed is selected, the resistor is bypassed, and full current is passed to the blower. I believe the resistor is $12 at an auto parts store. Good Luck Tim

The "blower motor resister" that slow the motor down to the slower speeds is broken or burnt out. The motor is running at it's default setting of full speed. The resister is usually located on the blower motor housing so it gets lots of air moving over it (it gets hot). It is held on by two or three screws and when you take it out you will see several different sized coils (one for each speed). Hard to get to easy to replace.

Items to check with blower motor:
First there is NO correlation to engine speed and blower motor.
Blower motor may be dying, Blower resistors are defective, on/off switch.
If there is no voltage to the reverse switch, then you have to back probe that wire and see where the open is.
The answer to your question yes there is a common connection. Probably at the fuse box. Like I said earlier you have to back probe wire to reverse switch and find out where it is open. Good luck

There is a blower resister within the blower fan that is replacable. Most likely this is the problem

Well if the motor is making noise the wheel could be broken or possibly gotten something in the cage where the wheel is. If the speeds of the motor dont work on any setting but high the resistor is out

Does it have an automatic temp sensor which adjust for cabin temp? Maybe that's going bad.