ok this suck i start my new job Monday and this is what the new year starts out as

last night we went out to dinner and everything was fine. this morning i went to go into town and the truck was dead..."truck is a 99 f-250"we are talking not even a flicker of a dome light. i checked and the lights were turned off so i though i left the dome light or or something. i pulled up the car and hooked the jumper cables on and i herd the blower motor turn on and i had the keys in my hand so i jumped the truck and let her run for 30 mins. i turned off the key and the blower motor was still on. you can turn it up and down and turn if off just like the key was on. i seen the air bag light was on to "the off light" and the abs unit was clicking on and off. the first thing i though was the ING switch went bad. it looked like it was the secondary ing that is on because the radio and other thing are not on. sooo i unpluged the ing switch and everything is still on so it's not that. i went around looking for a relay that was warm or clicking and nothing. i wiggled all the harnesses i could find thinking a wire rubbed through. i unplugged the abs unit and blower is still on. the only thing i have added on this truck is a cd player and trans temp gauge. i unplugged both of them. so i am thinking there must be a bcm or something giving power. i did unplug a box under the dash and that did nothing. so i need help because i dont want my baby to start on fire or something. i have the battery unhooked for the min

 

I used to have a link to a public library in some small town that had free on-line access to auto service manuals. You could see the wiring schematic. I'll look for the bookmark. I'm not sure if I still have it but I'll post today if I can find it.

 

thanks man i have been looking online and nothing good so far

 

Sorry, the only links I found for free technical service manuals are for my Jeep. I wasn't able to find anything for Superduty trucks. However, I did not find the library bookmark I was thinking about. I know it exists, I just need to hunt a little more.

 

At least on my 2001 diesel pickup, the blower motor has a 40 amp fuse and relay located in the battery junction box under the hood. If you pull the relay, you should at least stop the fan.

I will try to see if anything connects between the heater system and the air bags.

Do you have air conditioning?
Do you have an anti-theft or keyless entry?
Have you changed any wiring lately, like added something?

 

i pulled the relay in the box and the blower did stop...and i can turn off thew blower with the switch but the system is still powered up. but the abs and air bag light is still on. i do have keyless entry but dont know about anti-theft.

and i have not touched any wiring in over 3 mounts and the
the only thing i have done was new coil packs 2 weeks ago. i am a mechanic but dont work on small stuff lol. if i can get a wiring diagram for the hvac, abs, airbag system i can trace it out.

 

I did some more checking , and since you said you unplugged the ignition switch with no change to the symptoms, it looks like the power lead into the switch may be shorting to the power lead out of the switch.

This discription is from a 2001 pickup:

Power for these circuits comes from BJB (Battery Junction Box) fuse #20 (50A) through a LG/YE wire to the switch.

The circuits that are giving you problems are fed from the RUN position of part of the switch, which powers the GY/YE wire when in RUN.

Unplug the ignition switch again and look for contact between the LG/YE wire and the GY/YE wire. Make sure the problem circuit is still "hot".

The GY/YE wire powers the #22 fuse (10A) in the CJB (Central Junction Box) in the cab. If you can't fix the problem at the switch wiring, you might be able to pull that fuse each time you shut off the truck until you get it fixed. There should be no power to the #22 fuse when the key is OFF.

I hope this has been of help.

 

thanks man i am going to check that now

 

i just checked it out. and i pulled fuse #20 and nothing pulled #21 ing switch (50a) and then i pulled #22 instrument panel junction box (50a) and that stoped it. i pluged all the fuses back in and removed the ing switch plug. i did not find a lg/ye wire. i did find that fuse#22 had 3.62 volts all the time. key off with the ing switch pluged in or not. if i pulled the fuse the blower motor still ran. the hole time the everything is cutting in and out and after i checked power at #22 the blower turned off and the interior lamp relay started clicking and stoped. now with the key off everything is fine and the blower is not comeing on. this sucks because i know it's not fixed

 

There may be something going on with the accessory delay relay (or the GEM, which controls it) that causes the power to stay on. At least pulling the #22 fuse seems to reset the problem.

Keep us posted on your progress.

 

Did you notice any chaffed wires? Start wiggling any wires you can reach and see if the blower starts up.

 

yea i have wiggled the crap out of all the harness's and nothing different. it seam's like something like a relay or a control unit is bad. i just went back out and everything of off. i hate intermittent problems.

 

I got the link from a friend. Here you go.

http://search.ebscohost.com/Communit...E326E336133503

Be sure to bookmark this. Free and legitimate access to service manuals doesn't come along every day.

 

i tryed the link and this came up

The page you have tried to access has expired, please return to your Library home page to restart a session on EBSCOhost

 

I don't know.... I just clicked it and it works for me. Try clearing all your internet cookies.