I can say for sure that it doesn't happen to my 95, made in 12/94.

 

I'm gonna try my 97 Tomorrow

 

My 95 does this and it has a third brake light. I had posted this a year or so ago, and you all thought I was nuts, but my 99 didnt do it.

 

ya, some of you may remember me having trouble with all this, in my 97. i replaced the multi-function switch, and it still did it after a while, so i just repllaed a burned out third brake light, but havent noticed it doing it lately.

 

Would this also effect brake lights and blinkers? mine were working fine as well as the transmission, turned on my hazards while parked, they were not on when i returned (i figured my significant other had turned them off) than the transmission started acting up later. Trailer brake seemed like it was stuck on and light would not go off

 

I have the od light flashing , & 4way hazard switch deactivating od when pressed while running.
Its a 94 f250 e4od 7.3 idi.(2 Unnecessary builds) I researched down to the Psom chip , which fixed the slamming shifting problem originally.
Od light still flashes and the 4way switch kicks out overdrive causing high rpm. I read about reprogramming the Psom or something for that brake voltage fix ?! How do I do that. I have an older scanner?! HaHa.
I'm recuperating from an accident and my employer of 28yrs seem to not want me anymore, I'm kinda unable and disabled .SO.....
Can I: fix this myself, operate the truck w/out causing more damage.
Truck has 230k miles +- and electric trailer brake hook Up.
I'm going to do the dielectric grease and connector cleanse thing. Most all sensors were changed as I stumbled with shift slamming issue. ANY info would be very helpful.
Thanks In advance.
Gtxx
I have found that being disabled and unemployed is a full time job. Ha"!

 

Mine is a 94 7.3 idi ,e4od,
Signals don't bother anything, I can change lanes at any speed,hwy or town traffic. But don't touch the hazard button.......warp sped rpm if you're in od . I have a trailer hookup but was there when I got the truck. Pulled a uhaul loaded with a Taurus to past Plano Texas from I 10 Louisiana w no problems a few yrs ago in the rain most of the way w/no problems. Now od light flashes ?..I ain't got a grip on this yet. I'm still lookin for a pattern.

 

Are you referring to the back cab light as the third brake light?

 

I don't know how the 4 ways could deactivate OD. I think that's impossible. It's a known issue that the 4 ways can and will unlock the torque converter, which is what I think is really happening. There isn't a way to fix this on your truck. You'd need to get custom software in the computer to change it.

You need to read the codes to find out why the OD light is flashing. Here's one way to do it. Ford ? OBD Trouble Codes

 

I pulled the following codes/
26 maf out of range
23 fuel inj pump lever out of range
66 trans fluid temp grounded +290 F indicated
68 no definition available
When I drove it , after all gear shifts plus od ,I pressed the 4way switch and rpm's rose. Pressed again and back to Od. Od light still flashing. Didn't notice whn it came on but it was soon after I started truck and stayed on

 

Tried to send a video clip , didn't work .maybe try again w/ smaller file tomorrow so u can see the tach when I press 4way flashers switch.

 

Rpm will rise a little when the TC unlocks

 

But should it be affected at all by the 4way flasher engaging/disengaging.?

 

I don't have any help for this one.

When you run the key on engine off test you need to hold the go pedal on the floor or you will get this code.

That's why the OD light is flashing. You most likely have the wire to the temp sender shorted to ground.

Going back to Diagnostic OBD Codes I find this definition: Electronic Transmission – Transmission Oil Temperature (TOT) sensor was overheated -Transmissions. That fits with the code 66.

Read this post again, you must have missed where I said that's normal.

YES!!!!!!!!!!!!!!!!!. Read the quoted post just above this^.

 

Yes. That normal. When the flasher light up it simulates hitting the brakes.