4x4 light flashing

iv read through the workshop manual and still cant figure out whats up. when i put it in 4wd all wheels drive i had it up on ramps to check when its put back in 2wd just the rears go but light is flashing on the dash can any 1 help

The flashing light means that the 4wd controller did not get a signal from the vacuum switch (below the vacuum solenoids) within 15 seconds of selecting 4wd.

This usually means that the hubs did not lock due to a vacuum leakage, since you reckon that all 4 wheels drive there are a lot of checks to make.

The hubs may be locked all the time. In 2wd, jack up one front wheel, and turn by hand. If the front propshaft is rotating, the hubs are still locked. Are they plain black, or do they have some sort of twirly thing that can switch from "lock" to "free" (manual hubs)?
Select 4wd with engine running, the wheel you jacked up should not rotate by hand.

The hubs work, but the switch doesn't.

Engine running, engage 4wd. If you hear Clack-Clack from the front, the hubs are working.
Engage 2wd, you should hear click-click as they disengage.

my 4x4 light flashes i dident even realise there was any thing wrong as all 4 drive when in 4wd and only the rear in 2wd:huh:

mine was just a split pipe i fixed it now

When the car is in 2wd should there be a vacuum coming through the vsv2

I have checked vsv2 and could feel vacuum when 4wd was engaged if I block pipes at valves will that tell me if it's lines or the pressure valve because iv heard ppl block them off when fitting manule hubs