New to the forum and appreciate the help so far! Here's the deal.I bought a 93 f350 turbo 4x2 crew cab 2 weeks ago. Took it to the shop, had 1700 bucks worth done to it, rad. hoses, alignment, oil change, inj. o rings, fuel filter, etc. Truck is in shop now due to another fuel leak they are trying to fix. Anyway, some of you might have seen my previous post about my overdrive light flashing( failsafe). Here's the story on that. Was going to the lake and had to hook up my trailer, but it has the 4 pin connector and the truck has 7 pin, so my friend and I cut the truck connector , used the 4 wires, and capped the other 3(using elec. tape for now). Everything was fine until leaving the lake, when the overdrive off light starts flashing(great) seemed to drive ok besides the hard shifts, but it has shifted hard since I've had it! I've read some other posts about brake lights affecting the torque convertor (sp?) I don't have a code reader yet and the truck is still in the shop! hopefully I'll get it out tonite. Do you think the cut wires aren't completing a circuit hence the failsafe? I know I'm reaching here, but I just spent 1700 bucks and I'm hoping not to spend much more! Sorry for the lenghty thread. I'll get a code reader tonite and keep you posted. Thanks.

 

Bad grounds on the trailer will feed a brake signal back into the truck with lights on. Intermittent signal will make the TC lock and unlock.

 

The overdrive light is still flashing even though the trailer isn't hooked up! Do you think its the wires being cut(not a complete circuit?)

 

Disconnect the two batteries for 15 minutes, that will clear codes, reconnect. If the problem still exists it will set the code again next time you drive. Was the FIPL replaced if so was it set right.......

To set to specs:
With a warm engine and the idle speed set to your engine specs probably 650 in drive (curb idle).

Now with key on engine off. First connect the negative lead of a volt meter to the negative battery post, then place a paperclip straightened to slide up the side of the center wire for a good contact, touch the positive lead to the paperclip. Electrical connector must beconnected to the FIPL.

If your FIPL requires resetting loosen the small torx screws and attempt to attain the correct setting. You can loosen the large bolts on the bracket if necessary but try to retain the centering on the FIPL/blade.

Your trying to get closed throttle voltage: 1.1 V, wide open throttle voltage: minimum of 3.8 V but not more than 4.3 V.

If you can attain those #s then tighten the screws/bolts and ensure the voltage is at the correct setting after tightening. You can also do a slow sweep of the fuel lever from idle to WOT to see if there are any blanc (dead) spots, much easier with a really $$$ meter with capture mode. If you still find there are hard shifts or very soft slippery shifts you can adjust to suit your driving but be warned slippery shifts will burn the trans up.

 

thanks plc, will try this when I get the truck back and keep all posted.

 

ooops, no the filp was not replaced.

 

Also, for future reference, you can buy an adapter for $5 to go from your 7 pin to the 4 pin flat instead of destroying the wiring.

 

A short in the wiring for any lights on the vehicle will cause the trans to shift and lock and unlock like crazy. They must be on the same circuit or something. I had the same problem and found a short in the interior light wiring. Fixed the short, disconnected the batts for 15 min. and reconnected. Trans went back to normal.

 

Got the truck back yesterday, they said they found no fuel leaks, but when I picked it up there was oil under the truck! Oh yeah there's an oil leak but not fuel is what the guy says!Anyway, gonna get the codes read today (autozone) and see what comes up. Thanks for the suggestions and patience!