overdrive on/off light blinks
 

'93 F350 crew cab, 7.3 diesel, auto (E05?), 4x4, NOT turbo charged. I've been towing a light boat w/ or without a camper since the truck was new. Hills, flats, etc, 55 to 60 mph. No problems. A few years ago, I was going uphill with my camper and the overdrive on/off light started blinking. This was on the way home from a one week trip, and I'd done many, many hills prior with no blinking. A repair shop said the code read "Excessive torque converter slippage"; we fiddled with various things, and later they replaced the torque converter. That did nothing. A year later, they replaced that torque converter. That did nothing. It still blinks when I "stress it" going up hill with a 20' river boat, or a 16' trailer lightly loaded, or now even with just 1500 lbs in the truck. I am talking gradual 2-3% grade hills here, not just the big ones ( 8%, etc). The beast never indicates any slippage (sudden rpm increase) and I can eliminate the problem by pushing the button off, but that increase rpm from, for ex, 1800 at 55 mph to 2400 and my fuel mileage drops way off. The light will usually only blink when I really get lugging, as when a hill decreases my speed from 55 to about 40, but sometimes it blinks with less stress. I just towed an 8400 lb trailer with the same 1500 lb load in the truck and had no problems on the flats, as long as I would push the switch to "off", accelerate to 50 or 55 mph, and keep that speed after I pushed the button to "on". BTW: With the light blinking, the tranny functions like normal (shifts down when stressed, etc) but it shifts as hard as hell; apparently that is what it does to make you take it to someone to fix it. I can not believe that this is a torque converter problem; I know of three other F350s that tow a hell of a lot more than I do and have never considered pushing the overdrive switch off. Is this a vacuum problem? A mixed up idiot box sending bad signals? Voo doo? ANY IDEAS? Sorry to be so long-winded, but I wanted to get most of the info out there. This is a real pain in the neck. PLEASE ask any questions or give any opinions. Thanks a lot. John

RE: overdrive on/off light blinks
 

When was the last time you rebooted your computer. Some codes don't go away on there own and will need your help. Take the neg. battery cable off for 1/2 hr. and see if that doesn't help.

RE: overdrive on/off light blinks
 

Kiarasue: Thanks for the reply. I have unhooked the batteries a zillion times while on the road and everything works fine until I "overload" the tranny and the light begins to blink again, resulting in the tell-tale rough shifting. Other than shifting roughly, the transmission operates correctly even when the light blinks. I just can not believe the light "trips" with the lightest of loads on small inclines; this is clearly not "over-stressing the torque converter". Any other ideas? Shoot them my way. Thanks. j

RE: overdrive on/off light blinks
 

So you are saying that you can clear the code and reset the computer to a normal operation. The lite on the overdrive blinks to tell you the trans is going into "safe mode". You need to get a code reader on it after the blinking starts. You know your clearing the codes when you remove the cables. The trans is signaling for help.

RE: overdrive on/off light blinks
 

Yes, removing battery cable resets computer and tranny works properly; I have to do that when I travel so the tranny does not rip its guts out when it shifts. I have taken it in, blinking, several times and it keeps telling us "Excessive torque converter slippage". However, after two new torque converters and having it blink with 800 or 900 lbs in the truck and going up 3% grade hills, no one can believe that the torque converter is really slipping. That is not much of a strain for a 1-ton. Sure, towing 8,000 lbs up 10% grades is tough, but not 800 up 3%. Soooo.... we are all confused. What is REALLY happening to cause the tranny to cry for help? Is it really the tranny? I think a messenger has freaked out and am considering starting to throw different electronic parts at it till we find it; sensors, maybe even the "main computer". Thanks again for the thoughts; keep working on 'er! : )

RE: overdrive on/off light blinks
 

I just sold my e 350 ex van with a V 10 because of the tranny problem, the torque converter went bad to the tune of 1800.00 I towed a 7400lkb trailer and the od light started flashing one day while towing then when I shut it down it stopped. Ford had one hellofatime getting it to act up again but finally they got ti to and fixed the problem, they said it was a bad TC and not me but at 66kmiles I ate it. am writing to the big cheese to seek reembursement since the cs dept said politely to pound sand. find a Ford dealer and let them fix it.

RE: overdrive on/off light blinks
 

The Talls: Good luck w/ your operation w/ the head cheese. Yeah, maybe I should break down and take it to the dealer. Dang, dealers are usually so proud of their work, though, that I almost ought to trade it in on a new one and let them fix it on their dime. Later. j

RE: overdrive on/off light blinks
 

When my expedition was doing the same thing with the overdrive flashing it turned out to be the pressure control switch, unfortunately shortly after the torque converter did end up coming apart.