4WD wont engage

[BENNY]

Hi guys

I have problem with my 4WD, if i press the button 4WD is not engaging even when in the slippery surface and the dash board light is off, the wiring was checked and everything is ok, hey guys out there would you help me

Thx

Benny

[The Lang-Shankit Scunner]

Follow all the vacuum pipes from the alternator to the T-piece, to the right up to vac sensor and to the left up to the 2 electrical solenoids on the inner wing, mine are green, with the engine running take off all pipe joins and check for vac pressure, from altenator. If you have pressure there, the take off the solenoid pipes, and press your 4wd button and see if you get pressure from them (they should only give pressure when button is pressed). Also check the vac filter which is under the drivers side front wing, and pressure to and from it. If you have pressure from all of these, check one of the pipes hasnt slipped off of the actuator on the front diff.

If no pressure from 2 solinoids on inner wing, then sit in the truck and press the button on and off, and listen for clicking (relay) about the centr console, behind plastic under the stereo. If its not clicking, then it may be the control unit.

If it is clicking then go under the truck to the centre diff, and try and turn the front prop, it should turn freely with button off, and lock up with button on.

If that functions ok, check all the oil levels(particularly front diff (ADD) ).

When your happy all is ok, engage the button, and just put it in reverse for a few feet and then drive for a few feet, do that a few times and it may free it. You may have to do the same for disengaging.

Other than that, check fuses, check any one way valve blockages in vac system. Thats about all i can think of mate

[BENNY]

Thanks

My surf is 3rd generation
I will try and let you know

Thanks

Follow all the vacuum pipes from the alternator to the T-piece, to the right up to vac sensor and to the left up to the 2 electrical solenoids on the inner wing, mine are green, with the engine running take off all pipe joins and check for vac pressure, from altenator. If you have pressure there, the take off the solenoid pipes, and press your 4wd button and see if you get pressure from them (they should only give pressure when button is pressed). Also check the vac filter which is under the drivers side front wing, and pressure to and from it. If you have pressure from all of these, check one of the pipes hasnt slipped off of the actuator on the front diff.

If no pressure from 2 solinoids on inner wing, then sit in the truck and press the button on and off, and listen for clicking (relay) about the centr console, behind plastic under the stereo. If its not clicking, then it may be the control unit.

If it is clicking then go under the truck to the centre diff, and try and turn the front prop, it should turn freely with button off, and lock up with button on.

If that functions ok, check all the oil levels(particularly front diff (ADD) ).

When your happy all is ok, engage the button, and just put it in reverse for a few feet and then drive for a few feet, do that a few times and it may free it. You may have to do the same for disengaging.

Other than that, check fuses, check any one way valve blockages in vac system. Thats about all i can think of mate

[BENNY]

Thanks Veggie for your comments,

I did my homework my surf is 3rd gene I checked all the pipes are well connected up to the front diff.

But when i check vac pressure and is available before the solenoids but there are no vac on pipes going to the front diff even when the 4WD Button pressed.

Now how can i check whether the solenoids are working and secondly how to check whether command is coming in the connectors at solenoids connectors.

I will apprentiate any help

Cheers
Benny

Follow all the vacuum pipes from the alternator to the T-piece, to the right up to vac sensor and to the left up to the 2 electrical solenoids on the inner wing, mine are green, with the engine running take off all pipe joins and check for vac pressure, from altenator. If you have pressure there, the take off the solenoid pipes, and press your 4wd button and see if you get pressure from them (they should only give pressure when button is pressed). Also check the vac filter which is under the drivers side front wing, and pressure to and from it. If you have pressure from all of these, check one of the pipes hasnt slipped off of the actuator on the front diff.

If no pressure from 2 solinoids on inner wing, then sit in the truck and press the button on and off, and listen for clicking (relay) about the centr console, behind plastic under the stereo. If its not clicking, then it may be the control unit.

If it is clicking then go under the truck to the centre diff, and try and turn the front prop, it should turn freely with button off, and lock up with button on.

If that functions ok, check all the oil levels(particularly front diff (ADD) ).

When your happy all is ok, engage the button, and just put it in reverse for a few feet and then drive for a few feet, do that a few times and it may free it. You may have to do the same for disengaging.

Other than that, check fuses, check any one way valve blockages in vac system. Thats about all i can think of mate

[The Lang-Shankit Scunner]

It will be either Control unit or the solenoids. Or switch of course. Check for the clicking from control unit, not sure where that is on 3rd gen on 2nd its under stereo area behind the plastic, if that appears to be functioning, its more than likely solenoids. Get a power tester to the plugs on the solenoids, if no power work your way back. Have you checked the front diff (whether it locks up or not) when you activate it?

[BENNY]

Thanks

I just got out the surf and I found out that 4WD swich is Ok but no clinking from control box and front diff.
Should I remove the control box and check if it is ok.

Thx

It will be either Control unit or the solenoids. Or switch of course. Check for the clicking from control unit, not sure where that is on 3rd gen on 2nd its under stereo area behind the plastic, if that appears to be functioning, its more than likely solenoids. Get a power tester to the plugs on the solenoids, if no power work your way back. Have you checked the front diff (whether it locks up or not) when you activate it?