4WD won't engage. No lights. Just hear relay click

You mentioned you can hear a relay click when you press a button? If that is correct then the dashboard switch box must be doing something.

My own switch box developed a fault, basically the 4WD and 4WD-L were sticking on. That caused some unusual behaviour, but I did see a green light.

I suggest going through the 4WD fault finding guide in the wiki (link in my first post) and try to narrow down the fault.

I wouldn’t jump to the conclusion that it’s the 4WD controller, they are likely to be expensive.

I know you have checked the fuse, but there might be more than one fuse in the circuit.

There is a possibility that the transfer box is stuck in 4WD and the transfer box switch has failed. Certainly you wouldn’t hear a clunk from the transfer box as it wouldn’t move. The way to check this is see if the front prop shaft turns by hand, you don’t need the engine running and doesn’t need to be jacked. If it does the transfer box is in 2WD, but you might need to apply a little force as it will have to drive the front diff.

If it is locked solid then the transfer box will be in 4WD as the front and rear prop shafts are locked together. Again this test or condition should be covered in the wiki.

Robin

The car doesn't seem to be locked in 4WD. I can turn the front wheel when it's jacked up.

I did the test of shorting together the blue/black and black wires on the 4WD switch and then I hear the vacuum hubs seal and the 4WD comes on constant (not flashing).

When I disconnect the wire I hear the vacuum hubs disconnect.

I also tested the 4WD wiring and that showed 12V which is apparently correct.

According the troubleshoot guide, this indicates that the 4WD switch is at fault.

However, if this is the case, shouldn't I hear something from the transfer box when I try to switch to 4WD, and just not get the vacuum hubs connecting because the controller doesn't get the signal back from the 4WD switch that the transfer box has switched to 4WD?

There is no noise from the transfer box, so I imagine (maybe incorrectly) that the TB is not getting a signal from the controller to switch over?

Is there a way to test that?

Thanks,
Lee

tomlil01 wrote:

The car doesn't seem to be locked in 4WD. I can turn the front wheel when it's jacked up.

I did the test of shorting together the blue/black and black wires on the 4WD switch and then I hear the vacuum hubs seal and the 4WD comes on constant (not flashing).

When I disconnect the wire I hear the vacuum hubs disconnect.

I also tested the 4WD wiring and that showed 12V which is apparently correct.

According the troubleshoot guide, this indicates that the 4WD switch is at fault.

However, if this is the case, shouldn't I hear something from the transfer box when I try to switch to 4WD, and just not get the vacuum hubs connecting because the controller doesn't get the signal back from the 4WD switch that the transfer box has switched to 4WD?

There is no noise from the transfer box, so I imagine (maybe incorrectly) that the TB is not getting a signal from the controller to switch over?

Is there a way to test that?

Thanks,
Lee

You can’t test the transfer box for been stuck in 4WD by turning the front wheels as without vacuum the front hubs disengage the front wheels from the drive shafts.  You have to try turning the front prop shaft.

The transfer box engages or disengages the front prop shaft, once it is engaged the 4WD controller engages the vacuum hubs, only then will it not be possible to turn a front wheel.  If your transfer box switch has failed your transfer box might be stuck in 4WD, but the hubs are not engaged.  When you join the switch wires the front hubs engage.

Without the transfer box switch from working the 4WD controller will think your transfer box is back in 2WD and so won’t move it either way as it is already stuck in 4WD.

With the car in 2WD reach underneath and see if the front prop shaft will turn, if it does then your transfer box is in 2WD.  If it is locked then your transfer box is stuck in 4WD.  In that case the only thing which is likely to be wrong is a broken/faulty transfer box switch as you have proved everything else.

Robin

Thanks for clarifying. So I could turn the wheel to do the check, but only after connecting the wires to lock the hubs.

Anyway, I just tried and the front prop shaft does turn, so not stuck in 4WD.

I am still unsure how to proceed.

I am guessing the transfer box is not receiving the signal to switch to 4WD? But I can't see anything in the troubleshooting guide about this scenario.

Lee

Problem 10 in the following link

www.bigjimny.com/mediawiki/index.php/4WD...WD_switch_has_failed

The actuator in the transfer box or the actuator wiring has failed.

You could disconnect the actuator wiring and check it is been driven by the 4WD controller. If it is then either actuator has stuck or has failed.

Your problem could still be a fuse, there are two fuses associated with 4WD in the main fuse box, see

www.bigjimny.com/index.php/forum/7-jimny...nical/64974-fuse-box

I recently blew a fuse on my Gen3, the door locks stopped working. The fuse which blew wasn’t the door lock fuse, but another one and I only found it by taking each one out in turn.

Robin

Thanks again,, Robin.

I'll take a look at the actuator? Is it easy to change if it is that?

So, there is only 1 fuse marked as 4WD? You mean just check all the fuses?

Thanks
Lee

I don’t know how easy the transfer box actuator is to change, probably hard. The wiki suggests giving it a tap with a mallet, but I have no idea.

I would check all of the fuses in both fuse boxes, just in case one has blown, it will be quick 8n comparison to fixing problems with the 4WD controller or transfer box.

Checked every fuse in the car and all look ok.

Will take a look at the actuator and the wiring from the controller to the actuator at the weekend.

Will also try giving the actuator a knock!

test the switch, then test the wires to and from the switch to the TB, have you ever changed the TB oil?

You mean the switch on the TB that sends a signal to the controller to say the TB is in 4WD? I think the problem is before that because it's not even changing the gears in the TB to 4WD. Think it's the actuator or the wire to the actuator which should swap the gears to 4WD

TB oil was changed about a year or so ago when I got the reduction gears put in

Has 4WD worked since you put the reduction gears in?

Yes, certainly was working since the reduction gears. I used it quite a number of times.

I tried tapping the actuator and didn't help.

Also cleaned all the connections with contact cleaner.

Lee