DOC4444 wrote:
Hey Mustang,
Where did you get the TC "lock switch" for your PSD? (I have a 7.3 Excursion.)
Thanks,
DOC
All you do is buy a decent quality toggle switch and splice it into the TC lock wire that goes from your PCM to the trans ( I don't remember the color combo of the wire, and i'm not sure if it would be different for the excursion or not)
Works like this.
I used one of those crimp splice connectors (the one with the anti water slimy stuff) Ran the wire from the splice connector to the toggle switch and wired the other end of the toggle to a ground. Then when you flip the switch it grounds out the wire (just like the PCM does) and activates the lock on the TC. Now doing it this way you allow the PCM to still controll it when the switch is off, but Since it monitors the speeds in the transmission it knows the TC is locked and should not be so the O/D button light will flash as a warning that somthing is wrong. Thats just because the TC is locked and the PCM didn't tell it to be. So if your going along and lock it manually a few seconds later the light will flash, if you unlock it manually after the light has been flashing it takes a few shifts for the PCM to realize that its still commanding whats going on and the light will stop flashing. Its a very simple mod, and there are many ways to go about it by wiring it so you have a LED lit when its on, or building a small circuit that fools the PCM into thinking its calling the shots so the O/D light won't flash. I'm a simple kinda guy so i just put a switch and no fancy stuff I figured I can deal with the flashing light. You might be able to find more about it on powerstrokenation.com or on ford-trucks.com I will see if i can dig anything up on it, i know the wire i tapped was on the harness right under the brake mastercylinder.
Oh yeah, you MUST unlock it when coming to a stop sign or it will stall. Its just like driving a standard when its locked. And you may or may not look like a fool when you stall your truck at a red light in the turning lane...

Not that i have done that or anything lol

its a real bear when your running the first gen swamps gear style HPOP and the starter speed isn't enough to build the pressure for the injectors to fire due to the thinner oil when its hot and you have to jump out and give it a shot of spray to get it going.