2004 F350 tow haul light flashes and check gage light stays on

That light means that the shift points have changed on the transmission. This is to get better economy when hauling. If it wont stop flashing then there is a valve in the transmission that is bad or sticking. You will have to have it removed and overhauled..

Pull the main bulkhead connector on the side of the transmission and check for fluid inside the plug if so that shorting out the transmission electronics this is a common problem with ford transmissions if not check all fuses download the manual from ford owners.Com and your fuse box diagrams and fuse values are in roadside emergencies

could be the switch or modual.check wiring for worn through or earthing.

check your trans fluide oil for a burnt smell
if so replace ---mercon sp only in power shift trans
anything else will cause damaged
tow haul light fashing = trasmission code
need to scan probably faulty sensor chaff wire
dirty conection /partialy unplug junction
burnt fuse

check conection at transmision and transfer case make sur all pin are clean and straight
also corect oil is in mercon sp only for this automatic nothing else
just finish doing one for a freind landed up improper conection over transfercase

This is going to be a internal issue with a faulty intermdeiate or direct clutch meaning a overhaul is needed.

tranmission is sliping or low on fluid.is there a lot of miles on truck.engine not lossing power transmission is sliping.

If that light is flashing that means there is a problem with the trany. If you continue to drive it, it will damage the trany. I suggest you get it into a trany shop as soon as possible. I guess, I would take it to a private shop, that specializes in automatic transmissions, instead of taking it to a dealer.

climb under the truck! on the drivers side of the trans in the neutral safty swith unplug it and look for rotted connectors! if so repair damage! second go to passengerside near the rear of the trans ull see a plate that s being held by 2 7 or 8 mm bolts remove plate ! behind the plate there will b another plug do the same! inspect for corrosion

Does the trans fluid have a burnt smell and is it brown or dark brown as opposed to a red wine color? If this is the case then you may have a service issue caused by a clogged trans filter which is what this sounds a great deal like and the sooner you get the truck to the dealer or your mechanic the better as the trans in these are not cheap to rebuild or replace.