Hello I have an 05 ford F150 5.4 fx4 . I was wondering if anyone has an idea why when I switch over to 4 hi the light on dash wont come on ? the truck does go in to 4 hi but light wont come on the dash and seams to do it with 4 low as well . This is the first time this has happend ??any help please

 

I don't know about your particular truck but on many the light won't come on unless the front axle locks in. So I would say the auto hubs aren't engaging.

 

I'm having a similar dash light only issue, with 4x seemingly working in both modes. Mine blinks and is off most of the time. I'm driving in snow right now and it's very easy to confirm that significant traction improvement occurs with no distinct noise, so I'm thinking the 4x is kicking in. I am keeping in mind that most other posts, focus on the motor vs xfr case vs hubs and obviously for good reason. So, I'm deliberating if the flicker is just a short or an indication of something more serious.

I may be diving into the dash to check that out, but I will do the simple visual test (as other posts suggests) that the components are moving and engaging, first.