I recently had a resistor go bad and resulted in the wire at the resistor melting and at the heater motor. When I went to the junk yard all of the 99-02 f150s (nothing newer) had the same wiring connector at the fan mine however has a different fan motor connection and a special wire from the motor to the connector that would have went to the motors on all of the others. Do I have a 2004 motor that was used since the truck was built near the end of the year and how do I order the right wire?

 

I too have a 02 F150 with a bad blower resistor and a burned connector. I replaced the resistor pack with two identical ones from napa and I only have the two high speeds but no low speeds with both of the new ones. Do i have to replace the burned connctor to get the other two speeds? where do you get the connector ? thanks for any help.

 

I replaced the pigtail and the resistor assy and my symptoms didnt change. when the fan switch is on position 1,2 or 3 the fan runs at about half speed. when you select the 4th position it runs at full speed............. what next? anyone know how can you check the actual fan switch? Any other ideas? thanks

 

This site is two for two for me, with the blower resistor being the second easy fix I have found in less than 3 minutes on this site. This really is what the 'internet' is all about. 25 bucks for the part, a bit of contortionism involving a mirror to install, and I'm blowing hot air on all speeds again. Thanks!!!

 

I just replaced my resistor today because I didn't have the first two speeds... now all speeds work but I smelled something burning when I turned on the switch and looked at it and the coils on it are heating up cherry red... that can't be normal right?

edit.
I just went back and looked at it again, it only seems to get real glowing hot on the second position...

 

Had replaced my resistor previously (a few years ago) and the fan again started working only on high a few weeks ago. Pulled the resistor to find it intact. Plugged a new one in and still only had high speed. Plugged the old one back in and all the fan speeds started working as I wiggled the plug into the socket. Unplugged and looked at corrosion on the spade terminals and sprayed everything with dielectric cleaner. Plugged it back in and all speeds are working OK.

 

I tried a mirror the first time and had to comment to my dentist how hard it must be to learn to do everything in the opposite direction. Really messed with my mind trying to screw the screws back in holding the resistor in place.

 

[QUOTE=Auburn1997;3764886]I have the same problem with my 1997 F150. I didn't notice the harness trouble until after I had purchased the new resistor. I purchased the resistor based simply on the symptoms, before inspecting it. I would like more information on repairing the harness, which I would like to do without investing another $38. Are the plastic adapter ends pretty standard? If so, do I find them at an auto parts store or somewhere else? And are the wires soldered into it? Thanks.

Those look like molex harness caps. Not easy to get the pins out of the plastic, but can be done with a long tweezer. Might be easier to get new pins crimped onto the wires, then plug them into the cap. Any electro-mechanical shop would have the pins, cap, and crimping tool. (As well as the knowledge to crimp them properly)

 

question is, after I pill the resister, cannot find whrre the four prongs plug into. Can put finger in hole and nothing there
how does this connect?

 

I changed mine out over a year ago. I don't remember having any problem with plugging it back in. Sorry I can't help.

 

just want to say a big thank you to you guys that talked about how to change this resistor!! i stumbled upon this fix looking for something else. i have been living with High only on my fan for a couple of years, because i really didnt want to dump a bunch of money into tearing my dash apart to fix it. $22 and 20 minutes later it is back to working order last night! Thanks again!!

 

just an update to an earlier post. TJFitz in post # 26 said he ordered a "Blower Resistor Kit" Dorman 973-414 which has the resistor and a new harness end from Rock Auto. I just ordered it for under $19.00 delivered to my front door. Thanks TJFitz

 

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As I understand it... Loss of temperature control isusually the inability to control the heat inlet door within the airbox. If your temp is stuck in one position (same temp all of the time) it is most likely the actuator, which is located and replaceable from outside the airbox. If your temperature fluctuates randomly like mine did, it's a broken heat inlet control door, which is inside the airbox. Ford gets $900 for this all day job, which involves removal of half of the dash to get the airbox out and get to the 50 cent broken door to replace it. THERE IS A BETTER WAY: Use a dremel tool to cut an opening in the front of the airbox in order to access the door inside without removing the dash or airbox! After the cheapo control door is replaced, just use a hot glue gun to replace the cut out you put in the front of the airbox. TIP: Make your cut at a 45 degree angle so that your cut out panel fits into the corresponding hole when you go to glueing it back in. TIP: To keep this from happening again, do not turn the temp control to full hot or full cold and leave it there. Go 'full lock' and back off a tick from either end. This will extend the life of the door by keeping relentless pressure off of it while it is stationary. There is at least 1 company that sells metal replacement doors, but I found it to be cost prohibitive, especially after learning that I could prevent the damaging stress from cracking the plastic door by backing off a little on the temp control switch.

 

Sorry to disagree with your official Ford dealer, 15+ hour method of taking the dash out and all of that... but I skipped that step by just cutting a big hole in the front of the plenum chamber with a dremel tool, replaced the broken blend door, then glued the cut out panel back in place on the front of the plenum chamber. The dash and all of that just stays put, the door gets fixed, and nobody knows the difference (except the Ford dealer and my wallet). There are aftermarket METAL replacement blend doors available that are sure to be more durable than the OEM plastic unit. I found it to be cost prohibitive though. I think if you just avoid leaving the temp control on FULL hot or FULL cold, then the stress on the door is lessened and the OEM door should last longer. The actuator continues to press on the blend door eternally when the temp control is in the full lock position, so just go to full on, then back off a touch to relieve the pressure.

 

What could explain having the same problem (low speed fan on position 2 and 3, but high speed on 4), then replacing the blower motor resistor with no change? No reason to believe the new part is bad out of the box. No rust or corrosion on the old resistor. All connections are good. Thanks.
2003 F150 XLT 4.6