check the mechanical linkage to the pallet grab release and make sure there are no electrical harness's near it. If it is consistant every time you press the pallet grab release then check and see if that linkage is making contact with any wires. It may have rubbed one and every time it touches when you press the pedal to release it triggers the code.

I would start by doing the following:
1. Check static straps. Verify both are touching the ground with no debris wrapped around them.
2. Check for shorts to frame. Make sure you are above 100k ohm's of resistance to frame with battery disconnected.
3. Verify there are no wires open or shorted in the over mast cables.

Unit is from '95. There are no switches sensors or wires in the area of lock or the pedal-- just a mechanical cable operation between the two.. It only happens when you have to push real hard on the pedal to release the lock. The pedal makes a hard contact to the deck at that point. Then when you try to pull out of the pallet, it throws the code 53 and shuts down. The real question is what is code 53? If I new that I would know where to start. Any help is appreciated.

Why do you think that it might be the forward contact? If that was the case, then it would happen whether you pushed the pallet release or not. Lift the platform and look underneath. I believe that you will find that the pallet release is rubbing or causing one of the deadman switches to short, causing the Code 53. Let us know what you find.