Hello everyone , well my issue is similar to what has been described in other threads/posts, I have a 2008 E450 6.0 Diesel.
I replaced the shifter tube bushings, shifted perfectly while off and battery disconnected.
Assambled everything back together , hooked battery back, turn engine starts right up, let it warm up a bit, then apply brake and release e brake and when try to shift from park to drive, would not move, tuned off open switch to try to put in neutral and was not able to shift. Unplugged battery and open switch and no problem shifting, from park to first no issue at all.
So put it in neutral, plug battery back up, and started no problem, shifted to reverse, neutral, drive all the way to 1st no issue at all, however once put in park, not able to shift, unless repeat same process as before.

Does any one have encounter anything similar and any suggestions?

Thank you in advance for your help and suggestions and have a safe and happy Thanksgiving Day!
Reverend Om

Welcome to the site..

The shift interlock works off of the brake pedal position switch,, do the stop lights work normally?
Fuse F11 15amp in the Central Junction Box is circuit protection into the peddle switch. Check F38 10amp as well, 38 Hot at all times. It’s the voltage input into the ignition switch (Run/Start positions) and on out to the shift lock on the white/light blue wire at the interlock connector. Both, dark green and and white/light blue should have voltage present at the interlock connector with brake applied and ignition in Run or Start..
On occasion, the harness at the peddle connector with break from continuous flexing from the pedal movements. May not be your case, but if you check the dark green wire out of the pedal switch it should have voltage with the peddle applied. And, Hot at all times voltage on the light green wire in to the pedal switch connector..
If voltages are in/out of the peddle switch, and present at the interlock, possibly the interlock solenoid itself..

HayaPower,

THANK YOU! and Happy thanksgiving , I really appreciate you taking the time to give a helping hand (38 Views and only your response), maybe this will help many others.
I will follow your directions (now I need to find a fuse legend/map) the 450 I Own is a former transportation shuttle bus with the wheelchair lift. So I found one fuse box under the steering colum (just above the brake pedal), another one is located right above the driver (the body was built by El Dorado) and the last fuse box is the one in the engine bay (passenger side up front).
Inhave ordered the shift tube, plunger and the shifter stick (which seems I will not need to replace) so no loss I will return them, and funny I already ordered the solenoid, so I will start with the easy stuff and if none of them work, at least by elimination I will find the culprit .
Now I don't mean to be pushy or ignorant, another issue I forgot to mention is the battery drainage, would that be related to the shifting issue? Or is separate ?
I have made sure to turn everything off and still drains it, so what I have been doing is just disconnect them. The power passenger door does not work and the lift too, so I was wondering it could be a relay or fuse. I am Waiting to hear back from El Dorado industries to let me know where the fuses and relays are located.

Haya again thank you for your help and best wishes to you and everyone for Thanksgiving and the up coming holidays.

take care

Reverend Om

Happy Thanksgiving to you and yours as well..

If you need any specific or detailed shop info on the tasks your taking on let me know and I’ll email you the materials..
Hard to know on the draw issue since it’s a conversion, but depending on the add ons and OE, sometimes pulling the power distributions at the panels may point to a cause.. Have you measured the total draw?