97 F250 with a powerstroke in it.
Last fall I was having issues with the OD light coming on and off sometimes even just sitting at a stoplight. Driving .. the truck would shift out of OD all on its own.
So the opinion was the wiring from the OD button was bad. The truck was parked all winter and I just replaced the shift lever and button . Now the light stays on with the button having no effect at all.
I'm not sure where to go now. There were no codes and the truck worked fine when the shifter wasn't acting up.

 

Welcome to the site..

When you replaced the lever,, did you inspect the harness end run? They liked to chaff and rub through on the column housing.

 

I'll take a better look but after the connector it goes in to a large bundle. I will have a look though

 

Is it making an OD shift?
If you don’t see any harness issue (and not making the OD shift), either pop the shift button bezel off and remove the TCS and see if the truck shifts to OD, Or, if you pull fuse #17-10amp in the fuse panel should cancel the light and default to OD enabled..
The TCS is a momentary contact switch, and a signal switch input to the PCM, it’s not a direct circuit function into the the trans.. If the light won’t cancel, and it is making an OD shift,, checking the harness up top is job 1, then the PCM connector ohm tested to the TCS pins..

 

So I pulled the fuse and took it for a drive and it did not shift into OD. Put the fuse back and the light is still on.

 

How many miles on the trans?

OD light can come On or flash for a variety of reasons and internal concerns, over-temp, slip, mismatched ratios, solenoids etc.
So, drives well, shift scheduling/timing good?, positive shifts other than no OD?
Did you check for codes or a shop or ? If the shifts are spec other than missing OD, baring any internal issues, an option may be to back probe the trans connector P/Y wire and see if cycling the OD switch inputs to the PCM which then outputs cycling of the Torque Coverter solenoid On/Off. As well as ohm test between the lever socket and PCM connector.
With OD button removed, no fused power input to the PCM via the button, nor a chance of a failed button, since on initial start and Key switched Off to On, the system defaults to OD enable on startup.

If there’s no on/off function at the P/Y wire, chances are it’s forward of the trans.

 

First I would like to thank you for all your help. I took the truck into a transmission shop today to have it scanned. The weird thing was on the way there i was pushing the button in and out, mostly out of frustration, and it actually went out and shifted into O/D. Got to the shop and after restarting the light came back on. They spent 4 hours on in and found nothing. The pcm was not receiving a signal and all the wires tested properly and there were no codes stored. They thought that there might be a short but nothing showed up when they metered all the wiring.
So they thought the pcm might be bad personally I thing the solenoids might be bad because i read that they can be intermittent . I'm going to take the pcm out and see if there is anything out of place. Its making me a bit crazy.
Gas + Match and just walk away lol

 

PCM was not receiving a single at all?

The PCM uses the inputs from the OD switch,, and then the PCM applies/ removes the ground for the Torque converter clutch solenoid to activate/deactivate the function. (12v power is supplied to ‘all’ the trans solenoids from the PCM power relay when the key is in run/start)

Should be easy enough to check on/at the trans connector (pink/yellow wire) for ground being added, removed, or basically if the PCM is commanding the solenoid. Certainly seems it is, otherwise it wouldn’t be OD canceled.
But to help rule out a PCM internal failure/cause, Checking at the PCM connector for ‘both’ the cycled input voltage from the OD button to the PCM connector , as well as the remaining lamp ground circuit added by the PCM to illuminate the OD button when cancel is selected..

You/they could either back probe the PCM connector to check for Live circuit applications with a DVOM or a shop with a Breakout Box,, makes for quicker more accurate work. The PCM connector is removed and the B box is then installed inline. Test and Check points are then applied/made within the box panel..
PCM’s don’t fail at high rates, but can fail, a visual inspection, doubt it would reveal anything. Pins, connector corrosion, harness issues, not that unusual, but the fact that the system defaults to OFF and a continuous hard fail,, should be reasonable easy to isolate and check the OD switch for applications at the PCM connector to help prove it out. Meaning, if the OD switch is cycling at the PCM connector, it may point a boney finger at the PCM as cause.
Could also manually remove the grounding wire for the apply/release control of pressure of the torque converter solenoid as a resort of sorts. But again, if the PCM connector reveals correct OD switch function it then lends to an internal fault. But if button is function locked or with no cycling at the PCM, could be a short between the button and PCM.
The solenoid itself has no bearing on the OD light function..

 

Well I have made no progress and decided to go back to the start. Tried pulling the fuse and switch and took it for a drive. While driving a pushed the switch back in and it shifted into OD. I pushed it again and it down shifted pushed it again and shifted up into OD.
All this with out the fuse in. I don't under stand how this could be. My understanding of the switch is that it gets power from the fuse pushing the button connects the RY wire to the Tan/White which sends a pulse to the computer at which point the Pcm grounds the White/green and lights the light. So how can it shift with out the power ?
Problem is making me a bit crazy

 

If you pull fuse #17-10amp,, you verified 'no voltage' at the R/Y at the TCS connector itself? Switch removed, voltage on the T/W?

Along with the fuse removal for the TCS/Lamp check, the Brake Fluid Level Switch, Warning Chime, Diesel Warning Lamp/Display, Fuel Water Switch, Low Vacuum Warning Switch, Instrument Cluster, Switch Lamps should be missing voltage..