There's not a whole lot you can do beyond hooking up a test light or two and monitoring them, a 12V lamp wired across the red & black leads to the pump - that will let you know that the 4WD controller continually powers the pump module, if it doesn't wire the bulb between +12V and the 4WD switch on the transfer case see if that stays lit when the vehicle starts to move

Other than that, the best I could do is how you more pictures of the inside of the differential ...

I tend to agree with you, the problem is most likely internal to the differential - it could be the actuator leaking, or there is a short length of rubber hose between the fitting on the bottom of the housing and the actuator itself.

I suspect if I were going in there I would be considering replacement of bearings & seals - be warned - you're going to be pulling the differential carrier out of the third member, you will need to have the back lash correctly set when you reinstall it, and also pay attention to the "mesh pattern" - it is a specialist task and you only get one shot at it, get it wrong and by the time you know it's wrong, you'll need new ring & pinion gears.

Last thing - there's a nylon support bush that can be fitted to support the right side output shaft - I'll get you a part number later.

 

Thanks for that info, I fitted the shaft bush so no need to find the number. I will get the test lamp out one evening and have a play about. I thought about getting the system to pressure with a gauge between then clamping off between the pump and gauge then rolling that car a bit, that would show me if I’m losing pressure when the diffs turning or if the controllers asking for more pressure when it turns even though it’s not needed. Other thing I thought was put a balloon over the diff breather and if the leak is internal I would blow the balloon up a bit?
still doesn’t help me with determining if it’s the internal pipe leaking or the actuator.
I think if it’s the actuator I will just weld it up and fit manual locking hubs, sounds like the cheaper route if it’s the actuator

 

I thought about getting the system to pressure with a gauge between then clamping off between the pump and gauge then rolling that car a bit, that would show me if I’m losing pressure when the diffs turning or if the controllers asking for more pressure when it turns even though it’s not needed.

Bingo! That's the way to further pursue this.

Narrow it down to a pressure actuating bleed-off THEN an electrical intermittent open circuit, if need be.

2ND Gen, 4 Wheel Drive problems to include early (thru...

Greetings, Another newcomer to the forum here. I just picked up a 99 Chevy Tracker (60,000 miles and very clean) and have the common "4wd won't engage" issue. When shifted into 4wd, the 4wd light does not turn on and the front wheels are not getting any power. I've done the search, but still...

www.suzuki-forums.com

 

just a little update,
I haven't had time to do any fault finding as I've had a lot on but i have been out and used it the last couple of days in 4x4
seems to work for a bit then the light goes OFF (not flashing) and i lose front drive. while driving slowly i can shift from 4H to 2H and back to 4H and it doesn't turn the light on but as soon as i stop and try again the light comes on and its all good for a while. Also does it in 4L
Driving patterns don't seem to affect it, sometimes it stayed on for 10 minutes before faulting, sometimes 1 minute so i'm non the wiser.
I will rebuilt the pump again and fit new o-rings this time (Any idea what size i need to get?) this should mean i can 100% rule that out but i don't understand while moving would effect this? but then again if I've a leak somewhere, a leak is a leak and should always leak raher then when it feels like it so maybe electrical? i don't know.

 

I will rebuilt the pump again and fit new o-rings this time (Any idea what size i need to get?) this should mean i can 100% rule that out but i don't understand while moving would effect this? but then again if I've a leak somewhere, a leak is a leak and should always leak raher then when it feels like it so maybe electrical? i don't know.

The metric O-ring kits from Harbor Freight have the correct size, and it's unlikely, at least in my opinion, that the leak is anywhere outside of the axle housing - it is possible for the movement of the axle to twist the air line leading to it but you've already checked all of those.

I've had my pump apart a couple of times (there's a thread I did with pictures that show the internals) and there's no way for movement of the vehicle to cause anything in there to move.

 

4WD Freewheel air pump teardown

The 4WD free wheel air pump on my 98GV failed - symptoms were no 4WD and no green 4WD light when 4WD was selected. I checked the pump, it was turning on and running for 10 seconds before turning back off - hmmmm - sounds like a problem internal to the differential - one way to verify this is to...

www.suzuki-forums.com

 

Thanks for the link. I sent mine out for repair but I was curious about the internals.

 

Another update
I’ve spent a couple of hours going over everything again to make sure I definitely need to take the diff out before i got stuck in.
seems like it might not be that after all.
I’ve found that when the light does go out, the pump isn’t coming on which to my understanding it should.
for example if I shift from 2h to 4h sometimes nothing happens, pump doesn’t pump and light doesn’t come on.
if I start driving like this the 4x4 light will come one after a bit then go off again after a bit and so on.
So it’s now looking like an electrical problem.
I will dig out the electrical drawing and get my multimeter out at the weekend and start on that.
Is there any common places to start looking? As it’s intermittent I’m hoping it’s a connection loose of covered in mud.

 

I'd focus on pump and x-fer case switch connections / wires for starters.

From the FAQ'd thread...

 

I don't think you will find the 4WD controller on your 2002. I believe the 4WD controller functions were moved to the PCM starting in 2001.

 

There was controller origin changes mid-Gen production run I am led to believe as well. Found that years ago while researching and hearing from other members.
Possibly market driven and on select years / models only.

Chevrolet vs Suzuki and Vitara vs Grand, are other fluid points.

 

Case in point, old post (in part)...

Red Wire Always Hot

1999 Chevy Tracker 2.0L AT. My Haynes manual says that the PCM does all of the 4wd control, and I've verified this by tracing wire colors to the PCM. Not sure what that little black plastic box is by the fuses, but it's not a 4wd control module

But still...never trust Haynes in general anyways.

 

I would start at the pump module connector, primarily because it's easy to find, easy to reach - three wires, red, black & pink - connect a 12v test lamp between the red & black - it should light immediately you shift into 4WD (either 4H or 4L) - it may go out after 10 seconds, and we can deal with that if it does, but the important thing is that it lights at full brightness and does so every time 4WD is engaged.

Once this happens, you're 100% certain the 4WD switch on the transfer case is working and 98% certain the 4WD controller, whether it is a separate module or integrated into the PCM, is also working - the pump module can be "bench tested" off of the vehicle (it's easy to remove & replace) and that will leave the diff internals for last.

 

brilliant, thanks for the pointers!
I'm not great with electrics so to start with tracing all the wiring and give all the plugs and terminals a good clean up and go from there.

Just out of interest, is there away of bypassing all the controllers and that stuff and just put a switch onto the pump and turn it on and off when needed?
I would prefer for it to work as it should but just thinking about getting it going for now if i need to wait for parts to sort it

 

You have not yet determined whether your problem is electrical in nature or internal to the differential - if it's internal to the differential then bypassing the controllers etc., will not get your 4WD working.

 

Im pretty sure it’s electrical now from what happens last night.
i went out in it last night driving round some fields. To start with the light and everything worked.
the light went off after a while and stayed off then I got stuck in ruts and couldn’t get out because it was 2wd, tried going between high and low but it dug itself deeper.
I turned the engine off but left ignition on in 4h and checked the pump, it wasn’t running and I pulled the pipe off to see if there was pressure and there wasnt.
I stood there a couple of minutes deciding weather to phone the farmer for a pull or dig my anchor in to winch off when I heard the pump start For a couple of seconds. I checked the dash and the light was on so I started it and drove straight out.
the next couple of times the light went out I did the same checks and eventually the pump would kick into life and the light would come on.

from what I understand now after reading up about the diff mechanically the only faults is an air leak which would mean the pumps constantly trying to build/ hold pressure and the light would keep flashing or if there was a component failure inside it diff the light would be on but no 4x4 but these don’t fit my symptoms

 

I think I’m getting closer to the cause but I’m getting more confused.
Sitting on the drive ignition on in 4h light comes on.
Turn head lights on, light goes off.
Turn head lights off, I here the pump and light comes on.
Same thing happens with a few other electrical things -heater fan, hazards, electric windows

With the engine off the batteries reading 12.4v
But I’ve found if I turn enough little things on to get it below 11.9v the 4x4 goes off - at this point I thought I had cracked it, batteries done for but it still does all the above when the engines running and I’ve got 14.6v on the battery.

I have no idea where to go from here!

 

I have no idea where to go from here!

Are you saying the high-current devices (headlights, blower fan, electric windows) are pulling down the battery voltage to the point where the 4WD pump no longer runs?

That could happen if you had unwanted resistance somewhere between the battery's positive anode and the far side of the 80-amp BATT fuse.

Try running your headlight test while monitoring the battery voltage on pin 16 of the DLC. A noticeable drop in voltage on pin 16 could indicate a resistance in the supply line. On my car pin 16 supply's voltage to the PCM and the PCM supply's voltage to my 4WD actuator pump. Technically the DOME fuse supply's the voltage to the PCM but you can monitor it at pin 16 of the DLC.

 

I just ran the pin-16 "engine off" test on my car:
Head lights off 12.28v
Head lights on 11.62v
I'm losing 0.66v. You are losing 1.3 volts. That's a lot. I'm not sure the PCM can operate on 10.4 volts.

The smaller battery cable goes to the 80-amp BATT fuse. With the headlights ON, look for a 1 volt drop between the copper wire and the center of the battery anode. On my car that drop is only 55 mV.

 

Rather than follow voltage, have you considered using an amp clamp on the feed to the pump to ascertain what it is using.(amperage..).

It is a fact, you can have voltage but little to no amperage.. Also if you are testing with voltage you MUST load the circuit.. open voltage is useless..

 

First thing I'm going to do is chuck a new battery on as mine seems to be on the way out, i can't see it being the cause because i still have the problem with the engine running but it sits at 12.4.v even after I've been driving it all day.

Then i will check the battery cables like you say and see what happens.

I haven't got a clamp meter but i will see if someone at work has one next week and use that to help

 

Changing parts without proper testing is my main beef,, LOAD test the battery, chuck a new one in if it fails..

 

the battery with headlights on is reading 11.6v that's had it hasn't it?

On another note, I've been out this afternoon filling up feeders in the fields and woods, everything switched off and its stayed on and worked the whole time

 

The key would be what is the recovery voltage and time for recovery once HL are shut off..

 

ok, i'm not great with electrics as you probably guessed. Can you give me an example of a test to perform and i will put the results up

 

Test what.? Battery load test is not easy to do with basic tools, but if it cranks and starts ok after the headlights have been on for 5 minutes thats a good indicator its ok.

 

Bad connections are probablythe issue, just because they are tight does not mean they are good. Check all connections especially the grounds to the body from the battery. Remove, sand or clean both surfaces so they are bright and shiny, bolt back up. Many small corrosion points add to a big issue, a small resistance across several connections adds up

Even the main fuses get corrosion on the terminals

 

Great thanks, I will do as much as I can tomorrow,
I’ve got some dielectric grease so I will put that on the connections once cleaned.
I will report back tomorrow 👍

 

i've just been out to make a start and i've noticed i have 2v between the negative terminal and any body earth, is this normal before i carry on?

That was ignition on and head lights on

 

is this normal

You have unwanted resistance somewhere in the ground circuitry. Use 2013CV's technique to jumper around the ground connections until the 2-volt drop goes away. You can use a meter lead for this because you are only dealing with headlight current. Jumper cables would only be needed if you were trying to draw 500 amps.

The jumper will provide a path around the unwanted resistance. When you jumper the bad connection the voltmeter reading will head towards zero.

 

Nope, thats an issue, should be under 0.1V battery negative terminal to body, and same to engine block.

If you're measuring from battery terminal post to ground lug on body, you have a bad connection at battery post, or a bad ground lead, as in the crimps are corroded internally, got a jump start cable? Go battery negative to a nice clean body point remote to the point the existing lead is connected then measure again, if voltage goes way down, that is proof its in the ground lead,

 

That means you have a serious issue with the ground..