4 wheel drive not working

[imapetrolhead]

the prop turnes when you put it in 4 but thats it. if you jack it up and spin the front wheels the drive shafts turn as well, so im guessing its diff related?
any ideas

[stormforce]

have you checked the vac pipes as the front shafts are operated by vacuum.
Do a search for vac pipes and you will find a diagram of all the vacuum pipes needed to check

[imapetrolhead]

yea they seem ok, ive got no light on the dash either, ill just check the pipes again a mo

[stormforce]

when you put it into 4wd shunt the truck to and fro a few feet to help engage the 4wd.
Is the problem just on the switch or is it when you use the hi/lo lever aswell

[imapetrolhead]

right think im getting somewhere, the 2 solenoids on the drivers side. there is suction to them but not from them and the wires have been cut off and taped up. so theres either no power getting to them or the 2 solenoids are faulty

[imapetrolhead]

is there a fuse that would make them work?

[stormforce]

there is a 4wd ecu under the stereo behind the bottom plastic panel if that helps.I can't remember off hand if there is or where the fuse is but have a look in the fuse box under the bonnet and also the one in the drivers side side panel

[imapetrolhead]

ideal ill have a look in my breaker tomorrow and swap ecu see if it helps

[TonyN]

if you jack it up and spin the front wheels the drive shafts turn as well, so im guessing its diff related?
any ideas

Are you getting someone to hold the other wheel when you do this? If you spin one wheel the other will turn the opposite way if the ADD is engaged, of you hold one wheel then the prop will turn.

If the ADD isn't locking in your 4WD light won't come on either. If the light comes on then odd wiring issues aside, it must be in 4WD.

Just checking you're not wasting your time and its all ok.

[NiftyNev]

right think im getting somewhere, the 2 solenoids on the drivers side. there is suction to them but not from them and the wires have been cut off and taped up. so theres either no power getting to them or the 2 solenoids are faulty

No wires no worky. One engages the ADD and the other disengages it. Both are needed.

There's a positive and negative wire for each so check the wiring for power. White with black stripe is negative.

Nev

[TonyN]

Didn't see that post!

Its definatly not working then...

[imapetrolhead]

the 2 solenoids then, should they both come on at the same time or one to switch on and one to switch off, definalty electrical from those solenoids, no suction from them but there is to them

[TonyN]

They switch, one will turn the ADD on, one to turn it off.

You should be able to turn the ADD on and off by joining each hose to the supply hose to the valves

[imapetrolhead]

yes it works if i connect it to the brown one, then i can turn it off by connecting it to the other one, ive tried a different 4 wheel drive ecu all the fuses all the wiring but still no power to the 2 solenoids, wirings all good what now.

im lost apart from wiring an on and off switch in to the dash. which i dint want to do

[imapetrolhead]

can i just leave the vacum pipe connected to the pipe that turnes it on and leave it like that, or is that not best