Ok guys here's what's going on I was driving my truck and my power windows quite working I figured it was a fuse so I wasn't to excited about it I stopped and unloaded some scrap metal and then when I started my truck back up I couldn't shift it out of park unless I unplugged the brake pedal sensor or turned the key just out of the off position then shifted to neutral then started then I could put it in gear and go so I got home and started looking checked all my fuses all good then I realize the windshield wipers are not working either and the door beeper if you have your keys in the ignition also isn't working the horn isn't working the lights on the window and lock switches isn't working either so I'm kinda lost now gonna barrow a relay tester in the am but I'm kinda thinking maybe the computer ?? For all this to happen at one to,e doesn't make any sense to me that's a lot to all go in one shot it makes more sense to me that maybe there is 1 something causing all this any ideas please help

No horn
No power windows
No accessory lights on the window and lock switches
No wipers
No buzzer/beeper (like when you open the door and leave the keys in the ignition
Won't shift out of park without doing it with the engine off or the brake pedal position sensor unplugged


I've gone thru with a test light and got power to the fuses for everything but still nothing

 

New symptom cruise control isn't working either any ideas please help I'm lost here guys

 

Which specific model are you working on? F250 Super Duty? Engine? Transmission?

 

The engine is a 7.3L its a auto tranny but I'm not sure what model is it possible that moisture is getting in the computer? The reason I ask is I had a lot of rain this morning and the floor boards are damp now if so would a good place to start be the cab lights reselling them and waiting to see if it drys out? And starts working right again?

 

Hate to say , sounds like the GEM mod went south . When you said it wouldn't come outa park , that made me remember one doing that . Start by checking all fuses and grounds . Some call the GEM mod. the Body controll mod .

 

Agreed. I always call it a Body Control Module, but basically it is the computer for everything that ISN'T motor related on a truck that old. Somehow I'm betting water got in it and ruined it. More symptoms will creep up until basically nothing works. If you're on a budget you can probably pick one up at a junk yard cheaper.

BTW, if you have a diesel it is a SuperDuty. No one puts diesels in their half tons...yet.

 

^^^ If you get one from a yard , be sure the build #'s match . Even if they give you the wrong part , most yards won't give you a " refund" on electronics . The #'s are all different depending on build specs . 2wd, 4wd , auto , man , man 4wd , auto 4wd , lamp configuration , build date , ect, ect , ect, . GEM BCM ? Who cares . That black thingey under the dash that controlls too much stuff ! Glad my 78 ain't got one !

 

Ok so we're is the body control module at is that the one on the drivers side under the dash by the e brake ? If that's not it any special tools to get it out were is it ?

 

You will find the GEM behind the fuse box in the cab. The usual culprit causing GEM failures is a leaking windshield seal.

 

Did you check your battery voltage with a digital voltmeter or with a load tester? If even one of the batteries is going south, or there is corrosion on one of the cables you can have very strange things happening.

 

I don't have a digital volt meter unfortunately I'm gonna see if I can barrow one but haven't tracked one down yet I was gonna pull the gem module and look at it but the only stuff I see under the dash on the drivers side is a big silver colored metal module and I pulled it but all the connections look good and clean and no corrosion I even opened it up and looked inside it looked good clean and dry its behind a plastic cover to hold it in place the only other electrical stuff I see there is the fuse box and some of the wiring harness

 

Go to this website and scroll down to where is says "Wiring the Latching Relay". There are two photos in that section. Click on the top photo. In that picture, you will see a latching relay (added by owner) sitting on top of the GEM (black plastic box).

SpringerPop's Disabler


If you need to know how to remove the dash bezel, click here:
SpringerPop's Upfitter Switches

 

Wow ok yeah I see it no wonder I was having issues finding it its really hidden away in there and thanks for the links that's some really good ideas I woulda never thought of and didn't know could be done

 

Back to OP... Have you checked powers and GROUNDS ? I see many issues with improper grounds . I see puters tossed at vehicles all the time . Lots of them only have ground issues . Some power issues . I would check them both properly ! before replacing anything . Just a thought !

 

Ok guys thanks for all the help the problem is the fuse box tore it apart and cleaned it up as much as I could till the new one comes is and dielectric coated all the connections and got it working again but I also gained a new symptom the speedo gage quite working when I got that done any ideas