4wd not engaging
 

Ihave a 2004 f250 HARLEY DAVIDSON LIMITED EDITION ,CANT GET IT TO GO IN 4WD LIGHTS UP ON THE DASH BUT NOTHING TO THE WHEELS,IS THERE A WAY TO CHECK AND ELIMINATE CERTAIN AREA,IT HAS A SWITCH ON THE FLYON THE DASH.




THANKYOU
DAVE LACLAIR

Sounds like your electronic actuator is putting your transfer case into 4X4 but your front differential actuator is failing.
Kind of a dangerous situation, if your front actuator suddenly decides to work while your back wheels are spinning on ice it could damage your front diff.

put the truck in 4wd. jack all 4 wheels off the ground an put on jackstands. put the trans in neutral and turn one of the rear tires by hand. does the front propeller shaft turn? Do the front wheels turn? if the front prop shaft turns you know the t-case is engaging 4wd and the problem is the vacuum system that engages the front axles. If you have hubs that you can manually lock; manually engage both front axles. do both the front wheels turn when the rear tire is turned by hand? If yes, unlock the front hubs and apply vacuum to the supply lines to the vacuum actuators. if they lock up now, the actuators are good and there is a vacuum supply problem. disconnected vacuum lines are common.