On my 2007 2.3 2WD Ranger the blower motor will not function. We replaced the motor with a new one. We replaced the resistor. The 30A fuse is good. The relay is new. There is power at the fuse. There is power at the post where the relay goes into the fuse box. There is no power getting to the switch panel in the dash. It seems to us that the connection at the fuse box where the relay plugs in may be failing. Does anyone have any idea what our problem is? Thanks, Paul in Central Massachusetts.

 

Welcome to the forum

No, there is no 12volt at the dash blower switch, it is a GROUND for the blower, not "power"

The 30amp fuse wire runs to the Blower Relay(engine fuse box, #55), then if relay is closed, 12v goes directly to the Blower motor

Battery(+)-------30amp fuse-----------Blower relay----------------(+)blower motor(-)-------resistor pack================dash switch---------cab ground

The Vent selector switch activates the Blower Relay, using fuse #27 in cab fuse box, 10amp <<< check it
The speed switch and resistor pack are what Grounds the blower motor
Direct ground = max speed
Then each resistor in the pack lowers Ground contact so slower speeds

This is not new, pretty much all vehicles use the Ground to control the fan speed, its just safer than running 3 or 4 12volt wires which can short to ground, causing a fire or melted wires
If a ground wire shorts to ground worst you would get is the fan at high speed, lol

 

could be wiring issues wire off somewhere or even broken wire easy fix would be wire it straight up to where when you turn your switch on it comes on and when u turn switch off it goes off. Or wire to the battery n put toggle switch