Howdy, my wifes parents own a
2002 Caravan AWD LE.And they unfortunitely have DIAL UP.
Anyway, seems the awd doesn't work. They were stuck off the side of their driveway and the rear wheel wasn't spinning. Not sure what that means, but is their info. for the AWD system?

Next their front heater fan only works on high. Ideas?
Many thanks for any help.

 

awd doesnt mean all 4 wheels spin. if you're stuck you will have only one front and one rear wheel spinning. that's the way open differentials work. and if you keep spinning the snot out of the wheels, then you'll probably blow up the transmission, viscous coupler, transfer case and rear differential. heater blower is most likely due to a bad resistor block.

 

Great thanks much. Next 2 questions-
How does one check to make sure the AWD is working?

Where do I find the resistor block for the heater fan? Is it behind the glove box?

 

get stuck and if one rear wheels spins and one front wheel spins, it's working.yes it's behind the glove box but just dont be throwing a new one at it until you actually diagnose that this is indeed the failed component

 

Can you guys point me to any diagram of the awd system on these vans? Also, how do you diagnose a bad resistor block?
Thanks for the info.

 

The resistor block functions thru a series of resistors. in most cases high speed bypasses the resistor to provide full 12v to the blower for max speed. Thru resistors, the voltage to the blower lowers thus reducing blower speed. using a wiring diagram, factory service manual and multimeter, you can diagnose the problem relatively simply. A Factory Service manual will clearly describe the function of AWD system. Basically if the front wheels spin and the rears are stationary, a viscous coupler will transmit power to the rear wheels. A viscous coupler, for lack of a better description, acts similar to a torque converter. when the input spins faster than output, it transmits force thru fluid movement. Or maybe if you look at a centrifugal clutch, when you acclerate, energy is transfered to the driveline. On the AWD if you are driving down the road and all wheels are turning at the same speed, the AWD section is basically just freewheeling not driving the vehicle at all. Again get a Factory service manual

 

Oh, a resistor block. The whole "block" could be bad?

I'm really looking for information for someone else, so diagrams or pictures help a whole lot better.
But if there isn't any pictures or diagrams in this forum I understand.
And you must have a factory service manual for your truck. I have one for mine too.
But in this case there isn't a factory service manual. That is why people ask questions like this and look for answers in a forum because they don't want to get one.

 

every vehicle has a factory service manual, I see them forsale on ebay. Yes if the resistor block fails, so can every speed can fail as can just one. The unit is actually called the front blower motor module, the service on this is kind of like a mystery black box with nearly zero information on testing the module. I spend about 10 min researching this and it seems to me you need to replace the module. Sometimes its nearly impossible to solve everyones problem via the internet.

 

 

power starts at pin 4 and moves it's way through. If you have power on both sides of the blower motor then there is no path to ground. You find the open when the test light goes out. Hope this actually helps