Gents: two or three weeks ago I left the rover running in lot as i ran into store for morning coffee. When I returned, ac lights were on as if it were running but nothing was blowing. I later tried to turn on and she started blowing. What happens is she just randomly fades and stops blowing. I turn off, wait, and I can restart normally. I did have some burning smell yesterday and decided it was time to take a closer look.

I've done some research on here and I'm still not clear on what is a resistor issue or me needing a new blower motor.

This morning, in anticipating of me ordering some parts, I went under the glove box and started to dismantle just to see I was capable of accessing and remove blower motor and resistor.

Turns out I'm a failure. I got stopped when trying to remove glove box because the pin hinges require a special tool (as per some link I found on the net)

My questions are: is there a way around this special tool? It's tight down there and I can't understand how this special tool would work anyway. Or can I get this tool anywhere? And the more important question: blower motor or resistor?


Thanks for help!!

 

Maybe these will help. Not really a resistor like old trucks. The automatic widget sends a pulsed signal to the fan module and varies the power to the fan motor as needed. The smell of burnt electrical insulation is not a good sign.

From the shop manual:

When A/C is selected or the blower speed is manually selected, the ATCM energizes the coil of the blower relay in the
Battery Junction Box (BJB). The energized blower relay supplies battery power to the blower motor, which is grounded
through the blower control module. The speed of the blower is controlled by a PWM signal from the ATCM to the blower
control module. The blower control module regulates the blower motor voltage in relation to the PWM signal.
When the blower is in the automatic mode the ATCM determines the blower speed required from the comfort algorithms.
When the blower is in the manual mode, the ATCM operates the blower at one of seven fixed speeds as selected on the
control panel.

Note: PWM = pulse width modulated, a series of pulses that get longer or shorter based on the computer program. Allows a DC motor to have high torque at low speed. Recall toy trains? They would not move until you turned up the resistor speed control, then they would jump forward to some speed. PWM controllers allow model rail roaders to start off slow just like the real ones. Petty common around many industrial plants as well. The energy that used to be turned into waste heat by the resistor is now saved.

So the old school resistor pack has been replaced by the fan control module. Infinite speed control. For a lot more money.

 

Thanks but I'm still lost. Are you suggesting it's neither the blower motor or a resistor ? It's the "fan control module" that's causing the blower to spontaneously stop?

Thanks for help!

 

Yes. There is no "resistor" like older systems. There is an electronic module with more computer being used to vary the speed of the fan. Same results, at ten times the cost.

May also be a bad wire connection, they can make that burning smell when over heated and insulation melts back from a corroded connection.

 

Ok. The electronic nodule is the dash board controls?

Any idea if there is a substitute for the glove box removal tool? I'd like to go fishing around down there. I don't see that tool on the net.

 

looked like a handle that held a pin at 90 degrees so you could tap it out like a drift pin, but I've never touched one.

 

You don't need to remove the glove box to replace the module, just the under panel and you can see it, a little tight to get to and don't try it on a day that your back isn't feeling all that great, but not bad of a job.

 

Well, I replaced the ac resistor (and correct, didn't need to remove the glove box). I was straight forward and took me 20 minutes tops. Also swapped out my battery cause it was almost three years old.

Bad news though... Didn't resolve the problem. The ac still will randomly shut down. I'm just having a hard time thinking its the blower motor cause it doesn't want to seem to randomly turn off w the heat blowing. This is why I thought it has something to do w load management. Thought the ac might have been drawing more than the battery/alternator could supply and was somehow shutting it down. Not so much though.

Where does this leave me? The blower motor? (If so, anyone can explain to me why it seems to only happen w ac and not heat).

Lst but not least. ....could it be the damn relay?

 

Anyone? New blower motor arrived today and I'm going to tackle it tomorrow but truthfully I have no idea if the blower motor is the cause of my "blowing" to randomly stop. I'll report back but if there is anyone who can lend any insight I'd appreciate it. I'll be in for $225 in parts after the motor and resistor install (drop in the bucket compared to taking to dealer) but still uncertain if this is even the problem. Any wires down there I should be looking for while I'm down there for inspection purpose?

 

Blower motor or HVAC head unit are my thoughts. The AC being on means nothing to the electrical system, as it is mechanical. I don't know why on it not happening with only heat, and that would cause me to lean towards the head unit, but I have not seen one fail like this.