The second speed position on the HVAC blower has stopped working - all of the other positions work fine. Is it just the switch? How easy to replace?

Any other ideas why only that position stopped working? Trying to save a trip to the dealer or replacing parts that aren't broken.

'97 F150 Extended Cab

Thanks.

 

Could be one of 3 things:

Bad switch
Bad blower motor resistor
Bad wire

To isolate, grab a test light/ voltmeter and follow:

Leave your speed selector on the 2nd position (med low)
and go under the hood and pull the connector on the blower motor resistor (4 pin connector with the following colors of wires

Orange with black stripe
Light green with white stripe
Yellow and a red stripe
Black

Take your meter or light and check for voltage at the light green and white striped wire. If you got voltage then it isn't your switch.
If you don't have voltage at the resistor connector on the light green and white striped wire, pull the radio bezel (panel around radio) and take out the function selector panel --Take the (4) 7mm or 9/32 screws out and leave the blower switch still connected.
Check for voltage on the same light green and white striped wire.
If voltage is now present, you have got a broken wire.
No voltage present means a bad switch. If you have voltage at both ends, then you need a new resistor.


Hope that leads you to your troubles!!
If you need more help, let me know!!

Good Luck!

FordMasterTech

 

Just wanted to say THANKS for your help -

With your instructions I was able to pinpoint the resistor block which turned out to that one of the resistor coils had corroded off its connection -

I made a temporary repair with a twist of wire and bought a new resistor block the next day from a dealer.

I figured you saved me at leat a $100 if I had to bring it in to the dealer.

Thanks again.

 

No Problem!!!

Glad to help


FordMasterTech

 

That's great MasterTech, you are an asset to this board.