Dads got a 2005 F250 FX4 Ext. Cab (Gas
) and the 4WD will not engage from the cab. When he needs the 4WD he has to get out and manually lock the hubs (I am not even positive it is engaging when we do that). We have checked various fuses and played with the switch inside trying different things but can't seem to figure out what the problem is. I am not very familiar with his truck but I thought I would ask the forum before he goes and has someone take a look at it $$$. Any Suggestions???