4wd indicator switch/sensor

[nishby]

Thanks for this guys. I had the same problem, found my broken yellow wire, fixed it, and BINGO...4WD light works.

I still have no wheel lock light and I'm thinking the sensor must be somewhere in the vicinity of the front hubs. Does anyone know where the wheel lock sensor is or what the source of the trouble might be?

Shane.

[Green1]

Don't take this as gospel, but I think that the sensor for the wheel lock is also going to the transfer case just like that yellow wire was. It checks the lock status based on whether the front drive axle is being turned by the wheels instead of by checking the wheel locking mechanisms themselves (hence why it only reads the lock or unlock once you start moving, not when the vehicle first starts)
Of course the other obvious thing to check... is the bulb any good?

[nishby]

Thanks Green1. I checked the bulb and it's fine. All other wires in the vicinity of the transfer case seem to be intact but there could still be corrosion in one of them.

Has anyone else solved this problem?

Shane.

[konadog]

The first time I engaged the 4x4 the indicator lamp flickered and died, and since our bus came with perma-locked flanges there is no hubs locked lamp at all. Never missed either - they are superfluous and unnecessary. The 4x4 stick shifter indicates the transfer case position, and now that I have manual hubs I just remember whether or not they are engaged.
:)

[Green1]

since our bus came with perma-locked flanges there is no hubs locked lamp at all

most people with manual/permanent hubs have reported that the wheel lock light still works, that is why my suspicion that the wire is not at the hubs themselves but further back in the system (I also seem to recall someone on the forum stating it as fact some time a while back)

[Profister]

I am reviving this thread hoping that someone knows by now what exactly controls the 'wheel lock' bulb. The pulse generator which has been mistakenly referred to as the 'wheel lock sensor' is not capable of switching the bulb on/off on its own. All it does is signaling that the front drive shaft is rotating either by the t-case or by the front hubs. This leads to the conclusion that there is an ECU of some kind controlling the 'wheel lock' bulb. I wonder if our reputable mechanics can put some bright light on this non-documented topic. Where is the Black Box?

[RichD]

The black box seems to be specific to the Manual Transmission.

man4wd.JPG (69.37 KiB) Viewed 8404 times

Butch would know the answer to this question.

[Profister]

Nope, this picture does not apply to the case. I already went through all the sources including Australian, UK and Russian forums; hit a dead end.
Edit: RichD, if you bring this picture closer to your Delica and compare one to another you will end with scratching your head...
So, we are looking for an ECU that is analyzing the status of a 4WD/2WD sensor and the rotation of the front drive shaft (pulse current provided by the pulse generator in the t-case). The 'wheel lock' light will tell you the truth only if the front hubs work properly i.e. if the auto-locking hubs are broken and do not lock but the front drive shaft is engaged by the t-case the 'wheel lock' light will be lit because 2 conditions take place: 4WD is engaged and the front drive shaft is rotating. The light will stay ON if you switch the t-case to 2WD but the front hubs are locked causing the rotation of the front drive shaft.This is why the indicator works with either auto-locking or manual hubs as far as everything works according to the programmed logic. Literally it serves one purpose: dummy protection.
Now, to the best of my knowledge the only ECU in a L300-brick is so called 'glow plug controller'. It looks pretty sophisticated for only this purpose; you do not need a microprocessor and a couple of dozens of transistors to glow 4 plugs. The only picture of a glow plug controller I found was the one provided by Mystery Machine in conjunction with the locations of the glow plug relays but it had only 1 connector on a PCB. My ECU (let me call it this way) has 2 connectors. What is this bunch of wires for?
I do not believe our reputable mechanics did not solve this 'mystery' which should be documented somewhere unless this information is classified.

[RichD]

The 4WD indicator is operated by tiny japanese elves that live in rubber tunnels woven into the chassis of the Delica. They live off rice and soy sauce, and make hooch with the rice that they use in spectacular fire breathing shows - in fact this is what illuminates the dash light.

So, if the light goes out, try leaving sushi on the dash. Skip the sashimi.

[Ursula]

so my 4wd light isn't working. after reading this thread, i figure my wire is broken? i couldn't tell from the pictires just where i was to be looking for this magical yellow wire. i really tried looking under my van but can someone give me a clue? ex. : in between the rear tires a little further to the back, next to that thing that looks like a football with fangs and a boler hat.
I dont actually have a thing that looks like a football, i'm just saying if you say it's right next to the flux capacitor that holds dilithium crystals, i have no idea what you're talking about.
any help would be appreciated. i'm sorry that i know nothing about vehicles, but i'm eager to learn, and if you need your bicycle fixed for any reason, i'm a certified bicycle mechanic and can totally help you out. or if you need your accordion or stringed instrument worked on.
thanks

[nishby]

Look a little reward of the front wheels, left of the centre. It's down low, which likely explains why it is broken so often. You may have to wipe off some goo to see that it is actually yellow.

Nice to see another bike mechanic fixing a Delica. I like the problem solving (although more so when I'm getting paid).

[Ursula]

Yay! I found the wire! but alas it's intact. That means something else is broken. something not so simple. figuring out how to check the bulb today i guess...
thanks nishby!
bikes are so much simpler. you can see almost all moving parts from one point of view. and there's no bloody 4wd light.

[L300Foca]

So I got under there and unwrapped the bundle and repaired two wires (yellow and black I think) connecting to two red leads via bullet connectors running to the back of the transfer case. This repair got the 4wd light to illuminate (circled orange in above photo). I chased the yellow line back a bit but didn't find anything broken or particularly weak in appearance. So half the battle is won, which might be enough to calm me for a while.

Anyway I reverse frequently enough so it's not as if I"m going to be driving around for any length of time with the hubs locked.

--T

OK, I see the Wheel Lock light. Mine doesn't illuminate when the hubs are locked (red circle), but the 4WD light does (orange circle).

Can someone upload a picture of where the yellow wire connects, at the back of the transfer case?

[thelazygreenfox]

Rich I like your explanation, especially the fire breathing part. it makes too much sense now.

Ursula I was very good with bicycles but gave up on my L300 when I followed the two wires concerned. They turned into coaxial wiring so I stopped searching. The light never worked when I sold it.
I believe the pulse signal from the trans axle (?) has to be converted to a 12 volt signal for the dash light operation. This should require some sort of a "black box" under the dash or(?) but unless you strip off the wrapping and expose the coax wire you'll never know where the wire goes to.

No problem existed in my dash assembly but no 12 volt power was present to the light. Hopefully somebody will find the controller and take a picture.
thx
Wayne
TLGF

[originalkwyjibo]

I found something on the site that may be helpful to L300 owners. Not sure if it is the same for L400s. In the FAQ and downloads forum, subforum L300 technical, under the topic Paj Steering &L300 Front Axle Manuals on page 26-54 it shows a freewheel clutch engage switch. Judging from the diagram the Delica uses a IFS version of what is referred to as a CAD or central axle disconnect. This system has a decoupler mounted to a two-piece portion of the long side axle shaft and usually through the use of a vacuum servo can engage and disengage the front axle. This works mch like the shift fork assembly in a manual transmission as it works the couplers back and forth from one gear to the other and the neutral position in between. Think of your front axle being in gear when engaged and in neutral when disengaged. The engage switch would probably of a push button type or possibly a proximity switch likely similar to the 4WD engage switch on the transfercase. When the shift assembly has moved over far enough to engage the front axle it either pushes the button or the proximity switch senses the metal and the circuit is closed and the dash light illuminates. I couldn't figure out how to copy and paste the page to my reply but here is a link. http://www.delica.ca/manuals/L-300%20Ma ... 20axle.pdf Hope this is helpful.