Blower fan speed selector gone bad?

[762mm]

I know there are similar threads in the forum regarding the blower only working on HI (bad fuse), but my specific problem is a bit diffrent and doesn't seem to come up in the search engine.

Basically, my fan speed switch (with the small, medium small, medium large and large dots on it) only seems to work correctly in the last two settings (medium-high and high)... the low and medium-low speed (two smaller dots) are only operating at the same minimal output, pushing out almost no air.
Also, when I turn my climate control switch to "OFF", I can still hear the blower operating, blowing air onto the widshield at the same low output as in low or medium low settings (never shuts off).

Like I said, I found similar threads, but can't find an answer to this problem... I'm thinking the switch (with the little "dot" settings) may be bad, but why can't I shut the blower off comletely with the vent position knob set to "OFF"? This has been going on since I got the truck, about 18 months ago. At first, I thought it was normal - not I know it's not. Any input would be very appreciated, thank-you all in advance.

 

[Jason94sport]

Not sure on a 99, but on a 94 that's a sign the blower motor resistor is toast. On a 94 it's next to the blower motor in the engine bay passanger side.

 

[Crankcase]

Ah.....the "OFF" problem gave it away. Run a search for "Blend Door"

Basically there is a little vaccum operated door that swings to the different positions. It is prone to failign on 95+'s.

 

[gijoecam]

I was having that exact same problem. Found the cause the other day:

http://www.explorerforum.com/forums/showthread.php?t=131660

Should be back up and running this afternoon. Didn't have time to fix it last night.

-Joe

 

[762mm]

I was having that exact same problem. Found the cause the other day:

http://www.explorerforum.com/forums/showthread.php?t=131660

Should be back up and running this afternoon. Didn't have time to fix it last night.

-Joe

Thanks everyone for the replies... I read about the blend door problems, I might have that too with the no "OFF" position thing, but I can select hot/cold air with no problem (therefore it might still be good to some extent).

Joe, I took a look at your other post (and great pics) of the melted plug and rusted out connectors... Now, I'm not really familiar with the blower motor and it's components, but you mentionned something like $30 USD for all the parts necessary at the dealer... Would you happen to know what these parts are called by any chance? I just want to make sure I order the right stuff - of course I'll also have to check it out first, and make sure that is the problem on mine (most likely - it's insane how much salt/calcium is on the roads here during winter! If it wasn't for that, I'm sure I wouldn't have half the problems I have or had nowdays :fire: ). Thanks again.

 

[gijoecam]

Joe, I took a look at your other post (and great pics) of the melted plug and rusted out connectors... Now, I'm not really familiar with the blower motor and it's components, but you mentionned something like $30 USD for all the parts necessary at the dealer... Would you happen to know what these parts are called by any chance? I just want to make sure I order the right stuff - of course I'll also have to check it out first, and make sure that is the problem on mine (most likely - it's insane how much salt/calcium is on the roads here during winter! If it wasn't for that, I'm sure I wouldn't have half the problems I have or had nowdays :fire: ). Thanks again.

I forgot to grab the part numbers at home.... (Over-slept thanks to daylight savings time) I'll try and remember to post them tonight.

$15 for the plug, $15 for the resistor pack. You may be able to get an idea if it's the problem... turn the fan on low and leave it on for about 10 minutes. Grab the wiring harness where it goes into the resistor pack. If it's hot, you've got a bad connection there causing high resistance and therefore heat.

I got some good pics of the repair too. Just forgot to bring them again.

-Joe