Transmission Mod mistake

[Dieselnerd]

No, not my TC but a switch I installed myself to keep the TC from locking up until I have my trailer up to speed. Just so this doesn't happen to someone else, here is what happened. I cut the wire going to the transmission lockup solenoid (same wire you ground to force lockup) and wired it through a toggle switch. After installation, I went for a drive, let it lock up in OD, turned the switch off and it unlocked, turned it on again and it locked up. Great, everything works fine and I forgot about it until a few days ago. I was out of town about 200 miles north with my pickup camper installed. I was stopped waiting to enter a main highway and had the bright idea to turn the switch off and see how well it got up to speed since I had a fairly good load with the camper. Imagine my surprise when I stepped on it and it felt like I had just picked up a 10,000 pound load. It was slow, very slow until I got rolling. It was then I realized it had started out in 3rd gear and would not shift into OD even after I turned the switch back on. I turned off the OD switch to see if it would lock up in 3rd but that didn't work either. I pulled over to the side of the road to start out again but it started in 3rd. I shut down the motor and started it up again and everything worked normally. After I got home I tried it again and whenever I had the switch set to unlock the TC when I was stopped, it would start out in 3rd and wouldn't work properly until I turned off the motor and restarted it. The problem was caused by the transmission relay. I thought you only had to remove the relay and jumper it out if you were forcing lockup. WRONG! I removed the transmission relay and jumpered out the contacts and now my unlock switch works fine just like I thought it would when I installed it.