Hoping you guys have seen this issue before.

My heat & AC work fine, but the only position the fan selector switch will actually blow any air is on high. Bought an OEM replacement switch and installed it but the issue still exists. Any ideas/thoughts?

Thanks
Derek

 

Sure do, the switch selects a lead to the speed control resistor.
The resistor has one position burned open.
On the passenger side up under the dash you will find the resistor and it's power plug on the side of the duct work.
Two screws hold it in.
Take the old one out and be sure the new one has the mounting holes you need.
Good luck.

 

looks something like this. you will see the plug end... resistors are inside the duct for cooling.

 

Apperciate the help, it has been annoying to say the least

 

This issue is so common, it's in the HVAC FAQs.