Weird noise under dash, sounds like blower motor but isen't?
 

I have a weird whirling type of noise coming from under my passenger side dash. At first I thought it was the blower motor, kinda sounds like a wheel thats sqeaky when turning but its not the motor. What else is down there that could cause a noise like this? Its not horribly loud, the blower motor on speed 2 or the radio are loud enough to mask it, but its not right so I gotta fix it. Ideas? This is on my 98.

Re: Weird noise under dash, sounds like blower motor but isen't?
 

When does the noise appear?

Re: Weird noise under dash, sounds like blower motor but isen't?
 

:uhmk:It may be the level actuator ( Small Servo type motor that turns hot & cold air flap:uhmk:

Re: Weird noise under dash, sounds like blower motor but isen't?
 

Whenever the truck is on. Its why I first thought blower motor as I know that thing runs very lightly even with the HVAC turned off.

Steve- I just replaced that thing about a year ago, such a pain in the arse to get to with the dash installed! Hope that isen't it lol

Re: Weird noise under dash, sounds like blower motor but isen't?
 

:mm: I took the one off behind the glove box last fall got it in position for heat cycle and clamp a pair of vise grips ( Small) on it and it got me thru the winter??/ And just the other day I turn it to the cold position WORKS and after you take the glove box out it a easy access It control the levels ??/ they way I found out it was dis-functional was after removing the actuator was to plug it back in and toy with the dials??/ Mine was really really slow and if you squeeze the mechanical connection it would stop all together ??/ The cheapest I could find the actuators was at Rock Auto different manuf. starting at around $30.00 Make sure the your flap moves freely, no hang ups :waah:I been thinking about connecting cables (choke) but haven't found the lever that will work for the double D 1/2 inch mechanical shaft to the flap There's actually Three of these actuators one to the upper right of the accelerator peddle runs the levels from defrost to the floor??/ One behind the glove box in the lower left location, and one between the heater plenum box and the fire wall on the inside of the cab controls outside fresh air probably the most difficult to get to ??/See items 6, 21 , 24

Re: Weird noise under dash, sounds like blower motor but isen't?
 

You might try pulling fuses one at a time to narrow it down.

Re: Weird noise under dash, sounds like blower motor but isen't?
 

There's also 3 relays behind the glove box at lest on my 90 there are ??/

Re: Weird noise under dash, sounds like blower motor but isen't?
 

Part # 16 or #21..... Remove glovebox..... It's not too difficult but just be patient getting to the actuator. Remove actuator, keep it plugged in.... adjust temp control & watch if the actuator turns.... When re-attaching it.....

The important thing is be SURE you align the motor actuator CENTERED onto the 'key' on the airbox.
Actuator motor is female... 'key' is male..... You will have to attach the motor with being 'firm'....pressing downward against the shape of the airbox, THEN lightly press onto the box key. If you don't do this, you can miss the center.

Looking at the motor & key on the box, you will know what I mean.

There is a poor design mounting the motor.... the box section BELOW the actuator box has a moulded shape , that makes the actuator snug against the upper box.

Part # 22..... sits on top of a part of the lower airbox, that sticks out a bit, ...this is where you have to 'rub against, to line the actuator square to the key. ( You'll see )..... Be patient..... It took me 3 times to realize I had to put "a little english" mounting it, to center the parts.