I have fan on high but nothing on low or medium. Never messed with one before.

Also i dont get much air flow out of my dash vents. Someone said clean under the cowl. How is that removed.


Both on a 86 f150.

 

Low and medium speeds are controlled by a resistor block inside the blower/heater housing. The airflow across them keeps them cool. Sounds like yours is burnt out.

As far as the cowl, it is a bunch of screws that hold it in. Pop the hood, remove the screws inside the engine compartment, then in front of the windshield there are more screws inside the slots of the cowl cover. Get them all out, remove the cowl and take a vacuum to it.

 

Hey thanks. I know the screws youre talking about. I was thinking they may just hold that rubber strip on.

Appreciate it!!

 

I used to be able to find pics all over the web of the bullnose resistor packs and how to change them, but I am coming up with 0's this time.

 

It's under the blower fan. Remove the 3 screws that hold the fan on, remove the fan and it's right there. ~Bill

 

Don't have to remove the motor on mine, just the resistor pack. A Rusty picture coming up.

 

Here's the resistor pack on an 81 with factory A/C. Its the reddish thing just below the heater hoses and to the right of the back of the blower motor.

 

Gary, thanks a bunch. That made it very simple to find.
Here is mine off a 86 f150 no ac

 

They simplified it quite a bit during this era. But, it doesn't look like they will interchange. I think you'll find the resistor is toast, literally.

 

Can grab one at autozone for $23 bucks so ill probably grab that this weekend. Tomorrows project is to clean under the cowl. Wondering what ill find. When i look in it there is nothing but it may have washed on down.

 

I would not bother to pull the cowl itself as the stuff will have gone down further than you can reach. Pull the blower motor and clean in there. If that isn't enough, pull the kick panels and then the panels you see there - assuming you don't have the kick-panel vents. That gets access to where the stuff goes.

 

Cool. Thanks. Be nice to have a good heater rather than a warmer.

 

Yep. Fully understand. You should be able to reach the heater core with the blower motor and resistor pack out, so do your best to get all the stuff out from in there. The debris will smell like burning leaves on the resistor, and stuff on the heater core lowers the air flow rate.

 

JaysDaddy,

An additional little bit of information... my experience has been that if the blower motor squeals or turns slowly, the motor draws more current and then burns out the resistor pack. As mentioned previously by Stangrcr1, the intermediate speeds are controlled by the resistor, but high speed is a direct 12 volts.

What I am suggesting is to be sure that you listen carefully after replacing the resistor. If the motor squeals or is slow to start when using the lower speeds, you might also want to replace the fan motor. Do as Gary suggested and remove the blower motor for cleaning. While it is out, spin the plastic squirrel cage fan and make sure it spins freely.

Oh yeah, it is always best to remove the negative cable from the battery to prevent shorts.

 

You can disassemble the motor to some extent to lube the bearings. Or, while it is out out some light oil on the shaft and work it in. However, that won't get the bearing that is inside the shell on the end of the shaft. For those it is possible to drill the outer case and drip some oil in. I have a motor that my father did that trick on several decades ago and it is still working fine.