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Discussion Starter #1
Ok so im having some trouble and cant seem to find the answers. I have been doing so work on my 97 f350 I replaced the trans about 4 months ago then the turbo ebpv blew and lost a lot of oil so I fixed all that and when I got it back on the road the overdrive light would come on steady not flashing and I would lose overdrive. I could push the button and is would go off. it did that for a day or two now the light comes on as soon as I turn on the truck and stays on. I pulled the steering column covers and checked the wiring. no issues there I check the pcm connection and cleaned and greased it. I also check the button with a multi meter and it works right. and I am getting 12v on the center pin and 2 on the right side pin on the connector on the column to the shifter. not sure what that means. I also checked on the connections on the transmission. any guidance would be nice thanks.
 

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There is a short to ground in the wiring to the button. I know you said you checked that, but that's what is causing your problem.
 

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Discussion Starter #3
which wire on the column do what that was I can try and jump them. I have 3 and one has 12v and one has 2v not sure where they go or what they do thanks
 

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I don't have a wiring diagram, sorry.

One is power, one is ground for the light, and the other is ground for the switch.
 

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Discussion Starter #5
Ok so if I'm reading 2 volts on one of the grounds then that is the problem just have to find where that is coming from right? Thanks


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Discussion Starter #6
Ok so I cut the switch wire about 4 inches from the pcm and the light stays on. I then took a length wire and touched it to the positive on the battery and nothing. But if I touch it to ground it goes out and I get overdrive back touch to ground again and overdrive it disengaged. I thought I need 12v not ground so I put it on a temp switch and it's working. Am I missing anything


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I am having the same problem. 1997 Ford 7.3 automatic trans. I replaced the shifter and the button/ Ford OEM parts. The truck will still not go into Overdrive. The light is on.. but the button won't work. If I jump the ground on the shifter w/ a wire it will go into overdrive. Any ideas? Got all new parts too.
 

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I pulled the multi function switch off to check it and everything started working again. The next morning the od light was back on though.
 

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I know this is an old thread but I'm facing this issue now. Wondering if anyone has found a fix. I'm to the point of sending my pcm to be rebuilt. I have a 97 f250 7.3 auto. Which wire at the pcm did you cut to trip to ground?
 

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Check the harness where it exits the shifter handle, then also farther down the steering column for chaffed wires
 

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I have already replaced the shifter and button checked the VSS and wiring, the harness at the transmission and the range selector switch and wiring. I want to ohm out the wires but don't have a diagram so not sure which wire at the PCM I'm after?
 

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checked the VSS and wiring, the harness at the transmission and the range selector switch and wiring.
You checked a bunch of things that are not at all related to your problem. The problem is in the wiring inside the steering column. Take off the plastic cover from the column. The problem is usually where the wires enter the shift handle.
 

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I have removed the column. I repaired the wires, that didn't work so I replaced the whole assembly with brand new shifter, wires and switch from Ford. I checked the other parts because I'm grasping at straws at this point.
 

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Did you replace the wires that the shifter plugs into?
 

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No I want to check the wires between the shifter and the PCM with out unraveling the entire loom. I'm looking for a pin out of the PCM so I know which wires I'm after.
 

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I ask because I'm leaning towards the PCM going out. It won't complete the KOEO test I get an instant P0605 code I also get a P0603 which I know is more than likely the tuner. So if I can eliminate the wires going to the PCM I'll pull the PCM and send it in for repair.
 

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I don't know if this will help. I took the truck back to the trans shop had it scanned. No codes again. I drove with my scanner and this is a short video of what's happening. This is not me pushing the button it's changing on its own.20-01-22-14-08-45.mp4
 

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interesting on your video -- looks like a short somewhere
Yes, monitoring the wire at the PCM would be a good idea -- I don't have a pinout for your year to share tho
 

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OK, quick google search shows pin 29 as the switch wire
this would be a staring place to monitor with a light or meter
 
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