Environmental fan doesn't work at position #4

[Joihan777]

Hello,
I have a 2002 Rodeo Sport. The environmental control fan doesn't
work at position #4. #1-3 work fine but for some reason it won't
when slid up to #4. This is regardless of the other settings.

Last month the switch got stuck at number #4. It got stuck due to
lack of lubrication. I took it apart and re-lubed it with electrical grease.
But now position #4 doesn't make the fan blow. The switch still slides
smoothly and properly into that position however.

Has this happened to anyone? How did you fix it?
Are there separate fuses for the positions?

[amigo-2k]

http://www.automotiveforums.com/vbul...ght=fan+switch

http://www.automotiveforums.com/vbul...ght=fan+switch

[Mirock]

I would check a blower motor resistor,located in a blower housing, mine went bad although i had only #4 speed and non of the lower ones. Maybe in your case is oposite? Good luck.

[Canucklehead]

Originally Posted by Mirock

I would check a blower motor resistor,located in a blower housing, mine went bad although i had only #4 speed and non of the lower ones. Maybe in your case is oposite? Good luck.

The blower resistor block only has resistors for the first three fan speeds, the high speed switch position doesn't have anything limiting the voltage. The usual symptoms of not having any or only one or two of the low speeds results from one of the series resistors going bad.

If the three lower speeds are working but the high isn't you could have a broken solder joint in the block or perhaps a bad contact in the switch.

[Joihan777]

Hello All,
Thanks for the suggestions.
I figured out what happened.
The slider-switch itself somehow overheated and the plastic
bottom of it got soft enough for the interior copper #4 rail to descend.
That descent didn't allow the spring loaded contact plate to connect
to the #4 rail. So that's why my fan didn't work in position #4.
I have no idea why the plastic would have overheated like it did,
especially since the fuse didn't blow......Hmmnnn.
Actually, it rather looks like the rail shorted....maybe to much grease?
Got a replacememt HVAC control assembly from a junkyard.
All these years I thought it was hard to change out but it was ridiculously
easy and the whole job (including the dash) can be done in an hour.
So there you have it. If this happens to you, remember that the bottom
of the slider switch is s-u-p-p-o-s-e-d to be flat and smooth with no
bumps in it.
Thanks again,
johann