Hi, everyone, this is my first time posting so please bare with me. I have a 99 F350 super duty 7.3L turbo diesel, I've read a lot of forums about BCM,GEM Ignition switches etc. and all the things that do not work because of these things being faulty. The problem I have is not that things don't work is that they all work when they are not supposed to. I can have the ignition off and key out and I can still turn wipers on, radio can be turned off but clock stays illuminated, heater fan can be turned on as well, all with the key out. The little indicator light on the headlight switch stays on as well as the dome light, and as soon as I open the driver door it starts to chime. I don't know if it's the key in ignition, or head lights still on warning chime, but neither is on. I Have changed out GEM and fuse box (both came together, used) new ignition switch and key lock cylinder, problems still exist. I am at a loss, any help would be greatly appreciated. It still starts and runs fine.Does the GEM need reprogrammed, or do I have a bad relay somewhere stuck in the closed position?

 

Welcome to FTE. Electrical problems can drive ya nuts!!

One thought on the strange electrical behavior - Superdutys from that timeframe have reported weird electrical issues that result from Windshield leaks. Water from a leaky windshield runs down behind the dashboard and flows along the firewall. When fuse panels and the GEM module get wet, it can cause strange intermittent problems that gets worse with continued exposure.

Look under your dash board against the fire wall and the carpet to see if things are wet after a rainstorm/car wash. Get a strong light and examine the fuse panel to see if there's corrosion forming. Look for water staining on the GEM module and associated connectors.

If things are damp, obviously find the source of the leak and fix it. Sometimes the problem goes away once things dry out fully. If it's been going on for some time - then you may have to clean or possibly replace the affected parts again.

I had this problem on my '01 F350. Replacement windshield wasn't installed properly, and my dashboard started going wonky especially after a driving rain. After it was fixed/re-sealed, and things dried up, the crazy behavior stopped.

Hope this helps, or that other folks can chime in with ideas.

RWNJ

 

Thanks for the reply RightWingNutJob. When I replace the GEM and fuse box I had read about the possible water leaks like you said but did not notice any water stains anywhere and the gem didn't have any corrosion to speak of, but replaced it anyway. Still does the same thing. I have to pull fuses for chime and radio and for dome light every time I park it so they don't stay on,

 

Check the seal on the windshield, the symptoms you describe are very similar to a leaking windshield seam.

 

Thanks for the reply John but nothing seemed to be wet. When I replaced the fuse box and the GEM they were dry obviously and the problem remained. I made sure there was no corrosion or wetness anywhere. When I replaced the parts and the problem still was there I replaced the ignition switch and key tumbler as well and still the problem was there. There has to be something we are missing. Every time I read about water leaking problems they have things that don't work, everything works on mine, it's just that I can turn everything on with ignition off.
Jose

 

Jose, water can do very weird things. You could try spraying your windshield with water, depending where you live.
I'd ask the mods to move this to the 99+ 7.3L Forum that way you have others with the same truck looking at this...

 

I live in Michigan and when it started messing up it hadn't rained it's been really cold up here and no I can't spray water on it right now this time of yr, it was 24 degrees during the day. In fact we had some extremely cold weather three weeks ago and that's when everything started to go haywire.

 

Was there snow/ice on the windshield? I could be totally off base here Jose, but if there was heavy snow when ice and you're running the defrosters it would make sense that the water would leak into the windshield?

 

I understand where you are coming from with the water leak and the snow and Ice but when I took the old gem and fuse box off there wasn't any signs of water or corrosion on anything, I even looked along the firewall the floor up under the instrument cluster and there were no signs of water anywhere. Plus the new parts I put in were dry and clean and I still have the same problem as before. So I'm leaning towards no water leak issues. I took the Ignition switch off to check the A1 wire (black with green stripe) I read on another forum that if that wire has power to it with key out then there is a short somewhere. Even with ignition switch disconnected I was still able to turn everything on, don't know if that's supposed to do that, Is it?

 

With the lower ignition switch (not the upper key switch) unbolted from the column, can you find a spot on the switch where the radio, wipers, etc. turn off? The older ford switches had oblong mounting holes to allow some adjustment. The newer ones don't but that can be fixed with a round file.

 

Hi texinwa, thanks for the advice. I tried what you said and there was no spot at all where I could move the switch to where it would turn anything off. I'm lost,, I've tried everything everyone told me and there always seems to be power to everything still. There are no signs that someone might have wired everything direct to make it work. The only thing I can guess is the GEM I used was bad also. I guess I'll have to bite the bullet and take it to Ford dealer and pay them to figure it out.

 

Unless I need the GEM reprogrammed to my truck

 

Check out your trailer electrical hook up in the rear bumper.
I also live in Michigan, and I had a bunch of road salt and water get past the seal in trailer electrical port on a previous truck. This caused a short in the 7 pin connector. The short melted the wiring harness behind the connector, and caused additional shorts. The whole electrical system went nuts, all kinds of weird stuff was going on.
It took a long time to find the problem.
I replaced the wiring harness in the rear, and everything went back to normal.
Perhaps something similar is happening to your truck.

 

I would replace the ignition switch before going any further. It very well could be internally damaged and keeping everything on. They are not that expensive. If you want to check before you do replace it I would suggest unplugging it and see if all your little gremlins go away. If so then new switch.

 

Older vehicles I would say DOOR SWITCH but know newer have time delay relays on dome light etc, so I would say bad RELAY or bad door SWITCH. (ASSUMING TIME-DELAY built into relay?) Additional thought: When this problem first noted, had you done anything that required a blown fuse replacement?
If it is not a bad relay contacts/ time-delay relay bad, A hot wire in an unrelated circuit, but in the same wiring harness (section) may be shorted to the fan/ control, down-stream of the blower control. (My tale) I had a blown blower resistor/ thermal-fuse, found bad motor bearings, replaced, and lost it again a year later. This time, I found the (new connector) was melted that came with the (new resistor) that came w/ the ((new) blower motor. I replaced the whole assy AGAIN, rather than mess w/ a bad connection