Update on our 2003 Explorer XLT HVAC blower issue:
After replacing the resistor board with no joy, took a leap of faith and ordered a fan switch off Amazon. Had the best price over all options.
Motorcraft #YH1670, $21.01, free 2 day s/h with Prime.
Disconnect battery under....just in case.
Used a set of non-marring trim panel pry bars to pop out the center dash bezel. Seemed to be easier if you start at the bottom corners and work up on each side.
Highly suggest the non-marring pry bars, there are videos on YouTube of those using screw drivers and really messing up the padded dash and the bezel.
A decent set can found at any auto parts store, Harbor Freight, or online for around $10. They are handy to have around for many uses.
Be careful when pulling out on the bezel, the factory did not leave a lot of slack in the wire harnesses attached to the 4x4 switches or the HVAC cluster.
Pull straight out on the blower knob & it comes right off.
Reach behind and carefully pull the harness plug from the switch. Takes some force to get it off, at least this one did.
Once unplugged, push in the top clip holding switch to cluster and GENTLY pull out. Then pick one of the bottom corner clips and do the same.
The third clip appears to let go once 2 are released.
Pop the new switch in place, should feel the 'clicks' when the switch is properly seated.
Put the knob back on.
Plug in the harness.
Reconnect battery.
Test the switch.
If it was indeed the switch, all 4 speeds should work as normal. In our case the front controls for the rear blower also returned to normal operation.
Thought maybe that switch was bad as well. Once new dash switch was working, that one started working as it should.
Line up and press bezel back in place.
Put tools away.
Total time: 20+/- minutes.
