I replaced the blower motor resister due to the fact only had 2 speeds Very low or high. Still have the same problem. other possibility ?
Looks like resister has been replaced before by PO. Contacts all rusted , cleaned contacts same results, Switch or blower motor ? How to test?
Please help me out with suggestions .
Thanks in advance Stan

 

It would be helpful to know the year of the Ranger(always) as there were changes to the wiring over the years

Most likely Switch or wiring from switch to Resistor pack, most common was resistor pack but since you changed it................

Get an OHM meter and a long wire
Pull out the switch panel so you can get to the wires on the switch

There should be 4 wires if you have 4 speeds, 3 wires for 3 speeds
Should be same colors at switch and at resistor pack

Use OHM Meter and long wire to test if each wire is good, 0 ohms(or very low) from one end to the other.

Now depending on the year the switch can be either the GROUND for the motor or the 12Volts for the motor, GROUND is more common.
So test each wire at the switch to Ground in cab, move switch positions as you test, 0 ohms means good ground


You can also remove resistor pack connector
Then test each wire for 0 OHMS to Ground on 1 switch position, assuming a Ground system
So OFF would have no Ground on any wire
Low would show Ground on 1 wire, only
Med would show ground on ANOTHER wire, and only that 1 wire
Ect..........

If certain switch settings show No Ground on any wire then could be switch or the wire, so need to do the above in any case

 

2003 ext cab. Just changed plug & now have 4 speeds. Not too much differance between 2 & 3 ,

 

No there isn't, not sure why low, med, high was not good enough, med-low and med-high seems redundant

2003 Ranger uses GROUND control for blower motor
Motor gets 12volts thru Blower relay when key is turned on, fuse #16(40amp) both the relay and fuse are in engine fuse box
Switch on the dash Grounds the resistors and direct Ground for High