Another 70 series not going into H4

[scohar]

Hi guys i need some help, my 70 series wont go into H4 when pressed by the button (with hub lock button on) it has manual hub conversion that someone has done before me, I can get it to go into H4 by pressing both buttons and putting T/C shifter into L4 then back to H2 puts it in H4, I have checked the solenoids and if I play around with the hoses I can get it to actuate, the top solenoid is working, Vacuum on when H4 not depressed Vacuum off when pressed, although the bottom one is not working, Its not getting volatge at the plug, is this something common with hub conversions ie something saying the hubs are not engaged?

Its a PZJ70 5cyl one if that helps,

hub lock light works on dash, 4wd light only works when cycled through the T/C lever H2-N-L4-N-H2 (with H4 button on its in H4)

I hope this all makes sense.

[kbushnz]

Have the vac lines to the H4 solenoid been swapped over????
Just for giggles....If the above is correct....
With your truck in 2wd normal mode...High range....
Go and try and turn the front drive shaft by hand....
If it spins freely then its in 2wd.... if it doesn't spin.... then it has been activated and just needs the hubs in to be in H4...

[scohar]

in H2 with no lights on the front driveshaft moves fine, and also locks up when in L4 and H2(with the button pressed) but only once you have cycled through H2-N-L4-N-H2.

Pretty sure its something electrical as the lower solenoid has no power at it.

I had a look at the plugs going to the hub which have been cut off, should I connect these together to fool it into thinking the hubs are always engaged?

[Sadam_Husain]

I had a look at the plugs going to the hub which have been cut off, should I connect these together to fool it into thinking the hubs are always engaged?

sounds something like that mate, if you've got colour coded solanoids the brown one is 2WD and the blue one is 4WD

[kbushnz]

I had a look at the plugs going to the hub which have been cut off, should I connect these together to fool it into thinking the hubs are always engaged?

No don't connect them you will blow a fuse...or fry the magic box
The original front hubs are operated via a timer...
You push in the button, the magic box sends power to the hub for so many seconds then stops....
Thats all, there is no trigger switch on the hub to tell you they are engaged.....

I wounder if cutting the wires has shorted out the magic box or blown a fuse...