Hello and welcome to JustAnswer!
Do you have automatic temperature control or is it a manual system with a four position blower motor speed knob?
Do you have a voltmeter to do some testing?
We have individual temp controls for the driver and passenger and and a control to send the rear air to the rear controls.
Yes, I have a voltmeter.
Do you have automatic climate control? (In the front do you have a knob with four blower motor positions, or is it a variable speed blower motor control knob?)
Ok great. Start by dropping the glovebox door down to expose the blower motor power module, which is mounted to the heater box directly behind the glovebox.
Disconnect the three way electrical connector. Connect the black lead of your voltmeter to a good ground, set it to 20v DC. Turn the key on and probe the dark blue wire and you should see battery voltage.
Then set the meter to 200 ohms and probe the black/orange wire and read the resistance to ground shown on the meter.
Let me know what you see for both of these and we'll go to the next step.
This is with the blower motor on high, right? You should have had full battery voltage there with the motor on high.
Do you have a jumper wire? That 50 ohms bothers me a little, especially with the low voltage from the power module. If you have a jumper wire, take a straightened paperclip and insert it on the back of the connector on the black/orange wire and push it in until it contacts the terminal. Plug the blower motor connector back in and turn the motor on. Take a jumper wire between your paperclip and a good ground and see if the blower motor runs.
Sorry. Did't have motor on high. 13 volts on high. Still want
the other test?
You have to remove the recirculation housing from the bottom of the heater box. If you look at the bottom of the box you will see an electric actuator. Remove this, and then push up the circular drive piece that engaged it.
Then look around the lower recirculation housing and you will see the 8mm screws that hold it to the bottom of the heater box. Remove these screws. There will be one directly in the front buried close to the floor pan. This one is easiest removed with a swivel socket and long extension.
When you get all these screws out you can drop the lower housing out. Remove the three 8mm screws that hold the blower motor to the heater box, and while holding the recirculation door out of it's way, lower the motor down out of the heater box.
I pulled the blower motor and tested it on the bench and it works.
Any other ideas? Could it be the temperature sensor in the airbox? Can it be tested?
Are you still on line?
Sorry for the delay. Forced to go out. Married. I have 12 volts across the two terminals that feed the blower motor. When I short out the motor across the Orange/black terminal and the dark blue wire, the motor runs. When I plug it in, it doesn't. How can this be?
If you jump it to the dark blue and black/orange wires coming into the power module and it runs, but not if it's plugged into the power module then the power module isn't powering the blower motor.
Plug everything back in normally and turn the key on. Take a straightened paperclip and backprobe into the light blue/dark blue wire and jump it to ground. This shoudl make the blower motor run at full speed. If not, replace the power module.
You aren't backprobing the dark blue wire. You are backprobing the light blue/dark blue wire, the third wire in the three wire connector. Take this to ground and the blower motor should run at full speed. If not, the power module is bad.
I'm not sure how you are seeing 12v there either but the motor won't run. That's why we condemned the motor. Possibly there is 12v there that can be seen on a meter but isn't enough to support a load - it probably wouldn't light a light bulb either.
Yes, with a load device - a headlamp or fog lamp bulb. But, since you know the blower motor works and you have power and ground to the module, all you need to do is ground that control wire. If the motor doesn't run then replace the power module.
Does backprobe mean with the paperclip? Lots of Scotch tonight so this may have to wait until morning, but the answers will make sense then.
Yes, take a straightened paperclip and insert it into the back of the connector on the light blue/dark blue wire and then ground it.
It does sound like you need a power module then. We know the motor does work, the power module has power and ground, so grounding this wire should have made it run at full speed.
Yes, the power module is where we have been doing all of this testing. It's held into the heater box with the two screws, and has the two electrical connectors.
that is an easy one to get out..
thanks for warning me about that back screw on the housing. After two hours and using every tool I own, i finally broke the bracket and ripped it out. Went back in fine.
The older vans were even worse. The early vans of this body style had that screw coming in from the top where it's not possible to get on it with a socket unless remove the dash and heater box from the van. Needless to say there are alot of those heater boxes out there with this screw area ripped out of the lower half of the housing.
There is actually an RV section here on JustAnswer, you yourself could become an expert and answer questions too!
Have a great night!