Hey Guys & Gals, I bought a Ford F250 SD pickup, 2003 about a year ago. Well, the blower motor did not work, I bought it at a State Auction. I figured I'd start by switching relays with good known ones and that did nothing. Then I checked the fuses, all OK. I replaced the switch on the Dash, about $30.00, and that was not it. I finally broke down and bought a new blower motor and resistor and replaced those - it STILL does not work? Does anyone know of the problem and/or a fix I can try on this? I was to bring it to my local car shop, but I'm unemployed right now, so I'd like to save the money and fix it myself with your help?! I was thinking, well maybe it is a ground somewhere, but I have no idea how to start troubleshooting that if there is such a problem? It came with a light bar and back rack system as well, but I don't think that would interfere with something like this? It's a really weird thing, I have pretty much replaced everything - anyone have an idea on what is next for me to do and try? Thanks fellow Ford Enthusiasts! Mark
If you've switched the relays, checked the fuses, replaced the switch and bought a new motor and nothing happened then I would say it has got to be the wiring or like you said a ground. Have you checked the wiring to make sure it is getting power in the first place? Maybe something in this link will help: http://www.thedieselstop.com/forums/f27/blower-motor-not-working-83795/
Mark. Do you have a test meter, digital or analog? Check voltage at the blower motor connection, the Brown/Orange wire. If 12 volts is not present, broken wire ^^^^^^ from pin 87 of relay to motor connection, a bad relay, 40 amp maxi fuse is blown or no power to supply side of maxi fuse. If the 40 amp maxi fuse is good, check for power on both terminals of maxi fuse, Check pin 30 connection of the blower motor relay where it seats into the central junction box with the relay removed. It should read 12. something volts nominal battery voltage. This is the feed from the 40 amp maxi fuse. If no voltage present, wire/connection is broken from maxi fuse to this point. Install relay into socket, If 12 volts is present @ Brown/Orange blower motor wire then there is a blower motor speed switch ground problem. A wire may look good, sometimes it is a factory terminal crimp connection that has corroded, the factory male to female terminal connection is bad or the copper wire itself has a "hot spot" weak point inside the insulation. This blower motor system is a ground switch controlled thru resistors system.
Here is the ground controlled blower motor switch section. With ignition key on, and the control switch AC/Vent/Floor/Defroster set to anything but OFF, Check for ground at the Orange/Black wire leading to the blower motor with the blower switch set to high speed, this will be a direct ground signal to the motor that doesn't go thru the blower speed control resistors. If this Orange/Black wire doesn't read ground with ignition on, blower motor speed switch set to high and control set to anything but OFF, Try a temporary test ground wire from a fender ground point or directly from the battery negative to the Orange/Black wire of the motor. If the Orange/Brown wire is 12 volts positive and you put a ground on the Orange/Black, the motor should turn on, if not bad blower motor. You can use a small nail attached to the temp test ground wire to probe the Orange/Black wire terminal without removing the connection from the blower motor. DANGER CAUTION DO NOT touch the Orange/Brown wire with this temporary test ground wire. FOR SAFETY Wear safety glasses and the temp test ground wire should be fused @ 30amp, or it can/will blow the 40 amp maxi fuse and/or send a shower of sparks into the eyes or face. If you are not getting a ground reading at the blower motor connection (Orange/Black wire) the problem is in the blower switch wiring ground connection or a broken Black wire feeding the blower speed switch or bad speed control switch. The Orange/Black wire from the blower speed control switch to the blower motor connection can also be bad. Test the black wire for ground at the blower motor speed switch connector. There is always the possibility of a bad new blower speed switch, a bad new blower motor, or a bad new blower speed control resistor assembly. A factory male to female terminal or factory made wire to terminal crimp can also be the source of a bad connection, check all connections on the wire circuits being tested, male to female and terminal to wire crimps. If there is no resistant ground signals to the motor the problem is in the blower motor resistors or the wire(s) is/are broken leading from the blower motor switch to the resistors or the wire(s) is/are broken from the resistors to the motor connection (Orange/Black). There is also a fuse in the blower motor resistor assembly as well as a ground connection.
BLACK THUNDA~ No I haven't not yet anyway...I kind of figured that is my next step. Thanks for taking the time to reply top me and the link. I'll let everybody know what the outcome is. Mark ******************
Joe, aka...Roush PSD Interceptor WOW! Thanks so very much! Man, this is what I needed, some direction! And, thanks so much for taking the time to do this and to send this to me! I've been out of work since January, so I have the time to check this out, and I surely did not want to have to pay someone. Something like this is an unknown, so I'm figuring $300.00 or more to look at it, which I cannot afford to pay, not right now anyway. This group/forum is the best! I was able to help a couple people and it felt good. I appreciate it and like I said, I'll let you all know how I make out, if nothing else for closure, lol! Best, Mark *****************
