03 A/C problems
Fleet Mechanic
Joined: Jul 2010
Posts: 1,354
Likes: 31
From: Winnipeg
Fan not blowing on low only could be either the switch defective or maybe corroded wiring/connector at blower motor resister. As for truck too cold, turn the temperature control **** towards heat. If it doesn't warm, the temp blend door or motor drive may not be working which will involve trouble shooting.
Senior User
Joined: Jan 2010
Posts: 210
Likes: 0
Since the AC works 'great' on the medium and high speed, but not the low fan speed, it's the blower motor resistor....When I say that, I'm assuming you meant that NO air blows out of the vents when the fan is on 'low'. If my assumption is correct, then your issue has nothing to do with the blend door
There was just a post the other day about replacing the resistor, either search for it or I'll try and find it and post the link.
There was just a post the other day about replacing the resistor, either search for it or I'll try and find it and post the link.
Senior User
Joined: Jan 2010
Posts: 210
Likes: 0
Try this:
https://www.ford-trucks.com/forums/9...m-low-fan.html
steve(ill) also posted something similar in a different post on the 25th of last month...
"if you have lost a couple of the speeds, lay on the passenger floor and look up under the glove box at the hot air duct. there should be a small resistor block screwed to the duct with 4 wires going to it"
https://www.ford-trucks.com/forums/9...m-low-fan.html
steve(ill) also posted something similar in a different post on the 25th of last month...
"if you have lost a couple of the speeds, lay on the passenger floor and look up under the glove box at the hot air duct. there should be a small resistor block screwed to the duct with 4 wires going to it"
Fleet Mechanic
Joined: Jul 2010
Posts: 1,354
Likes: 31
From: Winnipeg
Just for information: The blower motor resistor has an overheating protection device (thermal limiter) which will open the resistor coil circuit when temperature reaches 121*C (250*F) interrupting the blower motor operation in all speeds except HI.
