Originally Posted by bidwell
It's been 6 years and nobody knows where the WOT relay is hiding? BTW it also affects the heater blower. Does Ford think the heater blower robs engine power too?
The WOT relay has absolutely no control over the HVAC blower motor.
If it appears
that the blower is turning off at WOT, then the flow doors are probably just shifting the AC flow from the dash registers to the defroster registers where it is much less noticeable. This is exactly what happens when HVAC vacuum drops toward zero at WOT.
Normally, a vacuum reservoir maintains vacuum to the HVAC controls and Pulse Vacuum Hublock solenoid during short periods of low engine vacuum. If the HVAC vacuum is dropping off at WOT, then there is a leak somewhere in that vacuum system. The Pulse Vacuum Hublock system which was used on 98 to 2000 1/2 4x4's is notorious for vacuum leaks but it could be leaking on the HVAC branch instead.
If you are still intent on looking for the WOT relay, there are diagrams in your owners manual and in the Ford Wiring Manual for your year Ranger. Be aware that some literature may call it the the "AC Clutch Control Relay" or simply the "AC Relay". Different names, same part.
Again, the WOT relay only affects the operation of the AC compressor clutch, not the HVAC blower.