heater only works on high

90ford4x4 · #1 (**permalink**) 11-10-2007, 11:39 AM

i just boughjt a 1994 ranger, an the heater only works on high, it has a new blower motor and a new switch, so what else could it be.

rangerfan · #2 (**permalink**) 11-10-2007, 12:04 PM

Can you hear the fan running at the lower positions?

90ford4x4 · #3 (**permalink**) 11-10-2007, 01:21 PM

nope it doesnt turn at all, only on high and thats it, its a new motor and new switch

87 XLT · #4 (**permalink**) 11-10-2007, 01:33 PM

The blower motor resistor is shot.

The resistor plugs into the heater duct. Might be under the dash or more likely it's under the hood near the blower motor.

Pickup a Haynes manual (20 Bucks) and a new resistor (also about 20 bucks) at any parts store.

90ford4x4 · #5 (**permalink**) 11-10-2007, 05:29 PM

ok that was my next thing to change

matthew71 · #6 (**permalink**) 11-11-2007, 04:45 PM

Remove the resistor before you go to the dealer to make sure the wiring harness isn't corroded too. I did the disassembly after my first trip to the dealer and ended up making a second trip. BTW the wiring harness is about $15.

rangersvt04 · #7 (**permalink**) 11-11-2007, 10:29 PM

resister is your problem. happened to my dads 99 its under the blower. its a ford only part.