Vitara 4X4 help

Hello all, I have recently brought a 2004 T/D Vitara and am very pleased with it but I have a fault with the 4x4 bit. If I move the lever
into 4 wheel drive the light on the dash starts to flash and the pump behind the front bumper is then running, I haven't checked the pipes or if there is any blow or is it suck from the motor yet but my question is: Does it work on air blowing into the diff or is it operated by vacuum, also what is it that tell the light on the dash to stay on( ie not to flashing) I am still trying to find the correct manual for this Vitara or some info. on the operation of said system but if anyone on the site can give me a clue as the sequence of the system or where to get the correct book of words that would be great. Thank you. John

Blow not suck

Not sure why the light would flash though? Presumably the same as the Jimny to say it hasn't engaged four wheel drive? Which would indicate an air leak somewhere?

In that original diff picture I posted, and the reference to the zip tied one, was because they are unreliable at engaging, hence why some owners lock them up and just rely on the transfer box's front prop being engaged (and fit free wheel hubs as well).

If you're going to be fitting larger tyres you could always swap the diffs out for Vitara ones? Available in earlier <'96 at 4.125:1 (41 teeth on crown wheel and 8 on the pinion or later '4U2' etc are 3.875:1 (39 teeth on crown wheel and 8 on the pinnion)

I have 04' 3 door Vitara with a flashing 4x4 light..... 4WD system is working well though, not sure what it's about.

OK thanks guys for the replies, I will try mine to see if the 4wheel drive is engaging with the light flashing but I have read that it has not engaged unless you have a steady light! Has any body else any thoughts on this please. I will post my finding when I get the time to get into it but I am a bit busy with other work just now. Thanks again