A/C blower problem. Please Help

[irishincali]

I have a 2001 mountaineer with a 5.0L The other day me blower went out for my A/C-Heater. The rear fan still works fine. I found a bad relay in the fuse box under the hood and replaced it. All of a sudden the fan worked, for about an hour, then poof, no blower/fan again. The compressor for the A/C is working along with the controls on the head unit. I can hear the flappers changing when I change vent modes. I started my engine then checked for power comming from the plug that plugs into the blower/fan its self. I get no power and if I'm correct, with the fan turned on I should get about 12V DC comming out of the fan plug. I have checked the fuses inside the cab and all are good. Does anybody have any idea what could be the problem? Are there any other relays that I am missing. Please help me if you can. It's gettin chilly in the morning and I need a defroster. Sorry for the long post, but just wanted to get everything clear as to my issue. Thanks

 

[robertoa1a]

A bad motor, associated wiring or circuitry can cause too many amps to be drawn through the relay thus burning up the relay. Check for a possible grounding problem, corrosion on connections and controls. Last and most expensive, a motor going bad can draw too many amps.

 

[budwich]

and how did you find your bad relay???? maybe its time to "find it" again.... doesn't sound good though if indeed the relay is gone.... BUT what do you mean "bad relay".... as bad could be "bad dog, don't do that" (ie. behavior) or bad contacts, or bad coil.... or not even bad as its something else not being "nice" to the relay....

 

[irishincali]

Ok, bought a new motor and installed it, still nothing.

 

[coonerboy]

Ok, bought a new motor and installed it, still nothing.

Did you check to see if the old motor was bad? Try to do some diagnosing. Pick up a manual that has a wiring diagram and also a multimeter. Throwing unneeded parts will only leave you poorer and more frustrated.

 

[scucci]

If eatc here is the chart for t-shooting blower inoperative in the manual. For non eatc there is no speed control, just a resistor pack.
Circuitry open/shorted. Check for voltage at blower motor and trace back.
A/C blower motor. If voltage to the motor - replace.
A/C blower motor speed control. Mounted on evaporator box under the hood. Common failure item.
Blower motor relay.

 

[irishincali]

Found the problem, was the blower speed control. Sits just below the actual blower. I do have ATC and wound out that was bad. Thanks for all your help, this is an awesome site.

 

[mhersh2356]

Bad Blower Motor And Relay

I have a 1999 Eddie Bauer with the Automatic Climate Control system. I had a similar issue and thought it was the blower control switch. I went to the junkyard and found one, plugged it in and no change. I then wiggled the relay and it started working then it stopped. I then went to the blower motor and banged on it and it started working again. I tested the voltage through the motor and found it was not good. I then started smelling the burning of an electrical device. I shut of the A/C system and it was the blower motor so I installed and new one along with the associated relay and it all works great now. For me it was the relay and the motor. The motor was drawing too many amps and cooked the relay and the motor.