Hello and Welcome back to justanswer..
The 4x 4 light flashing in this way is a fault light .... this means the Ecu / tcm - has detected a fault..which a diagnostic test would find the reason for..
Flashing 4 x 4 lights often happen when the front differential automatic disconnect is not engaging or dis-engaging when you select / de select 4x4 drive.
Common causes for this are ...
Front differential sensor switch is damaged or faulty
Actuator rod/shaft jammed / seized (perhaps sand/mud/dirt)
Vacuum lines leak/popped off fittings
Vacuum solenoid valves / sensors ... There are two... either of which can or may be faulty ...
Lastly , in the "common cause list "...electrical wiring connection issue (ecu/solenoids/switch) ....or any combination of all the above .
This is all quite involved though and you do need to know exactly what you are doing etc when working to find the cause.. If you are unsure, I would recommend using a local 4 x 4 specialist - who will know what to do / look for as above and this will ultimately save you money letting someone like that find this for you as it shouldn't take them long at all - and often, its not a costly fix..I Sincerely XXXXX XXXXX have helped you - but do ask me if you need anything more..
Kind Rgds, MIKE
- >>>>>>>>>Please don't forget ....Please press the ACCEPT button if you are happy with my answer/advice given - as that's how I get paid for my time, knowledge and expertise given. Thank you.
Feedback and any Bonuses are always appreciated too. Thank you.