2008 f350 4x4 dually tow haul not engaging indicator light not coming on after pressing button and fuse is not blown

Should be at the fuse block under the hood. If you have your owner's manual it explains all the fuses pretty good.

You need to have a diagnostic scan tool hooked up ,glitch in one of the control modules or a wire in the circuit shorting to ground ! probably something simple but hard to find ! With a factory scan tool they can check the input signal to the BCM ,PCM .
Tow/Haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul mode is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily toggled to zero volts. This signals the powertrain control module (PCM) or transmission control module (TCM) to extend the length of time between upshifts and increase transmission line pressure. Cycling the tow/haul switch again, or cycling the ignition switch disables tow/haul mode and returns the transmission to a normal shift pattern.

Mine was probably some kind of sweet drink. Works like glue when it dries. Had to remove the button from the switch assembly and clean with Windex. 1 hour. 2012 Jeep KK.

Th e tow haul button is so if your towing a heavy trailer its easier on the tranny when you hit the button you generally dont need to use it for everyday regular driving.

That is the Tow/Haul indicator. Button on the end of shift selector was most likely depressed during shift or possibly a malfunction with the tow/haul mode selection system. (IE: Tow/Haul button)

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

check your wires at the connection that goes to the tow haul button. under the plastic cover where the shifter connects. i ohmd the shifter to make sure it works when pressing the button and checked to see if power was coming up. first check the fuse. i had to ohm the two wires that went to the pcm and that is where i have my problem i think it is in the fitting . could be anything but i would start at the fuse then the shifter..

check all your fuses. If your lucky you might find one the is blown and could be related If not fuse related then you need to remove the platic steering column cover. Under there at the end of the shift lever you will find two small wires that are for the tow haul button. These wires get brittle and break over time from shift level movement it seems. You will have to repair the broken wire and you should be good to go!

most likely switch

Hi, the problem is when you are tilting the steering wheel all the way up it's putting to much tenstion on the wires that come outof your shifter that run to the tow/haul button. i am 99% sure your wires are disconected. rewire them and add some extra wire so next time there will be more slack in your wires.