We have a Cat 627B scraper I have been working on. The tractor serial number is 15S983. The scraper serial number is wore off but we believe it is 38V00045. The issue is the tractor and scraper transmissions don't seem to be on the same page as far as shifting goes. The previous owner rewired the machine from the transmission neutral/run switch to the back transmission. The most extreme example of what we are dealing with is the tractor trans would be in reverse and the scraper would be in a forward gear. Lightly pressing each gas pedal verified this without causing any damage. I verified all the wiring was good from the tractor trans switch back to the scraper trans switch. I also changed the scraper trans switch but it didn't help. I'm going to verify that the trans neutral/run wiring that was ran is indeed good. Any help or troubleshooting guides would be greatly appreciated. Thanks