When I switch to any 4WD position from 2H, I get flashing lights (they do not stay on). If I switch back to 2H, they stop flashing. I have a feeling the offending part is the free wheel switch, as this hasn't ever been changed on my vehicle and it's 10 years old. But I was wondering if anything else could trigger this issue? Thanks!

 

Thanks for that Mike, its not full time 4WD does that make any diference? So when you say the centre diff is locked does that make all 4 wheels drive at the same time and when thats not on they drive sepretly?

 

if the lights flash, you have a trouble code that will help you diagnos the problem. you can find the codes for the 4wd in the ABS ecu. most of the time its one or more of the switches on the transfer case.