Hi all, newbie here. As the title states , I have a 1995 F150, 5.0, 4r70w tranny and my overdrive button doesn't do anything. Is there a common part failure that I can look for first before I go to looking into the wiring and whatnot? I'm handy with a volt meter if its needed. Just need to know what color wire(s) to look for if it comes to that.


Ok, here is an update since the above was posted. I searched and found that i should check the button on the shifter...which I swapped with a known working one and that had no affect. Then I pulled the plastic off the steering column to check the wiring and it was in good shape where it entered the shifter. I haven't been able to locate which fuse should power it either which is what I should probably do before I go any farther if someone can help me with that. If its not the fuse....where do I go from there?

 

The wires break right where they enter the shifter handle. Sometimes they break inside the insulation and they look fine, but they are broken.

 

Thanks for the heads up Mark. I'll take a closer look at the wires again tomorrow and see what I find.

 

Update :

I pulled the shifter out completely this afternoon and I ohmed out the wires thru the shifter and at first they all ohmed out ok. I re-installed it and went to check for voltage. At first I had voltage, then as I was moving around my son noticed that the meter blinked for a second. Upon further inspection, the purple wire had a bad spot in it right out in the middle of nowhere. The outer jacket showed no sign whatsoever of damage. I could only tell it was broken by moving it. Spliced it back together and its working fine now. Glad to have it fixed because I need to haul some things to our hunting lease tomorrow and I won't have to worry about it shifting in and out so much anymore.