[Sco-tie]

My GVs 4wd light is constantly on now that i have taken out the air pump and put in a vit diff. Even with the red and pink wires from the pump disconnected and in 2wd the light is on and again when they are connected.
Any ideas why this would be? There is another closed plug with a cap on it next to it coming from the same loom that has 2 wires running to it one red and yellow wire and one grey wire.
Any ideas?

[fordem]

If it's on in 2WD I'd say you have a short somewhere.

On a functional system there is a 4WD controller which gets a signal from a switch on the transfer case and based on that it runs the pump and turns the 4WD light on, if I recall correctly by supplying a ground to the light - so the controller could be defective or the wire shorted to ground.

On a 04 GV that controller might be the ECU/PCM - on earlier models it was a separate controller mounted under the dash - I know they changed, I just don't know when.

If I were in your position, I would be tempted to find the wire from the dash cluster - disconnect it from the controller (what ever that is) and wire it directly to the transfer case switch, so that the light goes on & off based on the position of the lever.

[zoukshin]

I think I read somewhere that the pressure switch (part of the pump) has something to do with the indicator.
Someone actually took that whole pump apart to fix it and spoke about it. Maybe it's relevant to your case, as in, some wires may have to be connected together or grounded if the pump is removed.
I believe there is also a switch on the T-case (but IIRC it only activates the pump, which sends back a signal to the ECU, bringing up the light)

[edit] pump teardown here: http://www.suzuki-forums.com/1g-1999-2005-vitara-grand-vitara/43439-4wd-freewheel-air-pump-teardown.html

[edit] not sure if it's ok to share this info here, but the above has a lot of tech details that could be good for future reference. Hopefully it will Sco-tie what to do or give him ideas.

[Sco-tie]

Yeah I know all about the pump, but it means nothing as it has been removed as only 3 wires lead to it, power in, power out I have joined those wires so it is a direct link as i am not using the pump any more. The light only came on when the pump was removed which doesn't make me think there is a short anywhere. Before its removal the light wouldn't come on as the pump was failing.
This is the opposite problem to what most people have when removing it.

[zoukshin]

Did you check the Tcase switch ?
I find it hard to believe it would play up if the only thing you touched was the pump but who knows ?
It can only be one of the 3: T-case switch, Pump, ECU (for newer models)

[Sco-tie]

I hasnt been in 4wd for almost as year as i was doing gearing and lockers. Put the locker in and removed all the air pump. Then the light just stayed on. So i cut the red and pink wires from the connector, still on then joined them, still on. wiggle 4wd lever, still on. Havent checked the t-case switch. How do i get to it? Under the boot there is another sealed boot. do you undo the screws to release it?

[zoukshin]

Just checked the manual, it's poor on details for that topic. I haven't done it myself so I can't really tell, sorry.

[zoukshin]

Sco-tie; this might help; #6

[fordem]

zoukshin wrote:

[edit] pump teardown here: http://www.suzuki-forums.com/1g-1999-2005-vitara-grand-vitara/43439-4wd-freewheel-air-pump-teardown.html

[edit] not sure if it's ok to share this info here, but the above has a lot of tech details that could be good for future reference. Hopefully it will Sco-tie what to do or give him ideas.

The tear down is also in the Good Tech section of the AZ forums, in fact, it was written for this forum and then reposted over there.

[zoukshin]

fordem wrote:

The tear down is also in the Good Tech section of the AZ forums, in fact, it was written for this forum and then reposted over there.

Noted. Wish google was aware of that.

[fordem]

Sco-tie wrote:

Power in is meant to come from the transfer switch run through the pump and go back to power the light.

This is completely wrong.

First - the transfer case switch does not supply power to anything - when in 4WD, it connects the wire to ground, sending a logic low to the 4WD controller.

Second - the 4WD light gets it's power from the ignition feed to the dash cluster - the 4WD controller supplies the ground to turn the light on

The 4WD controller monitors the pink wire - if it sees a logic low it will turn the light off, if it sees a logic high, it will turn the light on - disconnecting the wire and leaving it loose will result in a logic high if there is a pull up resistor in the controller - ground the pink wire and tell me if the light goes off.

See Section 7E of the FSM for the details.

[zoukshin]

fordem wrote:

disconnecting the wire and leaving it loose will result in a logic high if there is a pull up resistor in the controller

seems quite plausible since it's negatively switched.

Edit: See the diagram (7E as Fordem said) - It IS pulled up to 12V. Resistors and +12 are shown. That should explain it.

[Sco-tie]

Ok then that was my mis understanding. The light goes off when I earth out the pink wire as in that state doesn't come on when in 4. So what do I have to do to get it to work?

[zoukshin]

I'd say you need to wire it to the t-case switch if you have removed the pump altogether.
Problem is, pink needs to see a logic high for the light to come up then ?
That's normally controlled by the pressure switch (opens when the pressure is enough to engage the diff).
Looks like the easiest is to keep the pump and plug the diff pipe. Otherwise you need to create a form of logic inverter from the t-case switch (IE relay with NC contact).

By the way, the other sealed plug that comes with the pump assembly is the airbag sensor I believe (that's why it's in the bumper)

[Sco-tie]

Hmm odd as other have done the same and removed the pump and just joined the red and pink wires together. No other wires needed. Also I don't think it's for the air bags aren't all of those wires covered in yellow conduit?

[zoukshin]

Are you sure you don't need a resistor or something between red and pink? looking at the diagram, there should be the pump motor and/or the release valve wired between these two.
As for yellow conduit, haven't found any on my car so far (maybe it's too dirty )
If I find out again about that sensor, I'll let you know. I had this information from somewhere. But there is a reason it's in the bumper, not like the pump.

[zoukshin]

Well ... according to the manual, section 8A-3-17 lists that harness with connectors A128 (pump assy) and A130 (low horn for van models). what do you know, there is no f'n reason for that whole assembly to be in the bumper for any of us then.

WTF is a GV 'van' anyway ? a EU-only model with a raised roof, a flat cargo area and no back seats it seems http://www.youtube.com/watch?v=bwMEiKyWZsU

[fordem]

Sco-tie wrote:

So what do I have to do to get it to work?

Check the second post in the thread - wire the light straight to the transfer case switch - if I recall correctly one wire is black/orange and the other orange/black - both wires will be close proximity near whatever device controls (controlled) the pump, whether it was the ECU or a separate 4WD controller.

Edit - I've corrected the wire colors - it's orange not yellow.

[zoukshin]

Fordem, I think I get you now, you mean bypassing the ECU entirely by hardwiring the light itself (not the sensewire) to the tcase switch (ground) from within the dash.
Ok now that's a good trick. Will keep it in mind if I ever change gears/put a locker.