Does The Definitive Tod Off Switch Thread Exist?????

[JoFotoz]

Spent a while this afternoon reading through all the TOD OFF switch threads....now I'm :confused:

With the TOD unplugged under the passenger seat, I get no crazy TOD lights...

...and the front drive shaft doesnt turn at all ( yes hubs are disconnected)


This is the result I am looking for ...but with a (simple?) switch...

...rather than the pain in the...(y)... unplug deal.

No a great electrical guy...a fellow VX'er and I are working on a simple solution...

...does it exist already?

Thanks

jo

[VXorado]

I have the TOD off switch with the resistors and my front drive shaft doesn't spin nor do I have the check light.

Recently, I installed a relay and incorporated an Isuzu OEM 4WD button into the dash. I can now switch between 2wd/TOD on the fly with no check lights. Of course, I would have to turn the hubs to get actual 4wd.

Does that answer your question or are you looking for something else?

[JoFotoz]

Yup...thats what I want too!


I have the TOD off switch with the resistors and my front drive shaft doesn't spin nor do I have the check light.

Recently, I installed a relay and incorporated an Isuzu OEM 4WD button into the dash. I can now switch between 2wd/TOD on the fly with no check lights. Of course, I would have to turn the hubs to get actual 4wd.

Does that answer your question or are you looking for something else?

Do you have a wiring diagram..or a link?

:thumbup:

Jo

[VXorado]

Here ya go. I got the resistors and relay at Radio Shack.

The relay isn't included in the how-to but is very easy to install if you want to use one for a factory switch. I can get you the part # if you go that route...

http://www.vehicross.info/modules.php?name=Content&file=viewarticle&op=newarticle&id=74



...Thinking about it more, maybe you can get around the resistors if unplugging the ECU doesn't cause a check light. I wonder if putting a switch on the ECU 12V wire would be the same as unplugging the ECU? Then you wouldn't need the resistors or relay and it would be a really simple modification.

[JoFotoz]

Thanks!!

That is one of the thread I read....but my brain aint wired for wires!

But I'll pass it on...and I'm sure it will help.

:thumbup:

Jo

[yellowgizmo99]

VX where did you add the relay for the factory switch in the wiring?

[pbkid]

...Thinking about it more, maybe you can get around the resistors if unplugging the ECU doesn't cause a check light. I wonder if putting a switch on the ECU 12V wire would be the same as unplugging the ECU? Then you wouldn't need the resistors or relay and it would be a really simple modification.
ya, i dont think you would need resistors if you just cut power to the ECU instead of cutting off the clutch/solenoid.

judging by the write up that you guys are referring to... the person who wrote the thread actually put a switch in line with the front speed sensor, not the solenoid clutch.
I've done some research on this at work (for a fellow VX'er), as I have access to factory wiring diagrams from Isuzu, and the solenoid should actually be a yellow wire.

:)

[VXorado]

VX where did you add the relay for the factory switch in the wiring?

The relay replaces the aftermarket switch shown in the write up & the OEM 4WD switch is installed on the 12V power for the relay. When the relay is energized it connects the ECU to the resistors & de-energized it connects the ECU to the clutch.


ya, i dont think you would need resistors if you just cut power to the ECU instead of cutting off the clutch/solenoid.

judging by the write up that you guys are referring to... the person who wrote the thread actually put a switch in line with the front speed sensor, not the solenoid clutch.
I've done some research on this at work (for a fellow VX'er), as I have access to factory wiring diagrams from Isuzu, and the solenoid should actually be a yellow wire.

:)

You would think a simple power on/off would work, but it might trip that insanely annoying check light... I just don't know.

[blacksambo]

The ball ramp mechanism physically prevents really turning the VX front dive off completely electronically. So, it's basically unescapable without disconnecting the front drive shaft. Sorry.

[vt_maverick]

I have the TOD off switch with the resistors and my front drive shaft doesn't spin nor do I have the check light.


The ball ramp mechanism physically prevents really turning the VX front dive off completely electronically. So, it's basically unescapable without disconnecting the front drive shaft. Sorry.

I've heard both those statements before in other threads. VXorado, want to prove your point with a video? blacksambo, do you have a diagram or some schematic that proves electronic disengagement is impossible?

[JoFotoz]

My front diff is toasted...bust it up in Moab.

With the TOD unplugged and the front wheels free spinning...

...the shaft does not turn at all.

How do I know..?

Because when it did turn in Moab.....

...the front diff sounded like a bag of nails, and jammed up now and then.

So..there ya go...thats my experience of this "debate"

jo

[blacksambo]

We know of people who do the electronic disconnect and get virtually no better gas mileage; that's one way to tell you are still operating with the same physical apparatus draging on the system.

[VXorado]

I've heard both those statements before in other threads. VXorado, want to prove your point with a video? blacksambo, do you have a diagram or some schematic that proves electronic disengagement is impossible?

I can check it out when I have a helper.

I assumed that the drive shaft was not turning because it doesn't transfer any power to the front diff. Also, another member who also had the TOD switch told me the switch would stop the drive shaft from turning. I haven't checked because of the kilby skid plates block my view.

...It also makes sense that the front drive shaft always has some synchronized spin.

I'm interested to find out myself :)

[Cobrajet]

We know of people who do the electronic disconnect and get virtually no better gas mileage; that's one way to tell you are still operating with the same physical apparatus draging on the system.

So, using this same logic, if I have three people in my VX and my mileage remains the same, that means my VX passengers exist in a weightless environment?? :)

(Hey, BS, I'm just pulling your chain!!)

I think putting the VX on jack stands and taking a video of the front driveshaft with and without the bypass engaged MIGHT provide a better argument.

[Vendetta]

I know I'm "answer shopping" here because I asked this earlier (http://www.vehicross.info/forums/showpost.php?p=252304&postcount=6), but this is the quest for the definitive thread after all. 'Rado's answer makes sense, but... Does anyone have any real world experience with simply engaging/disengaging the TOD via switch, without messing with locking hubs?

Goal is to be able to simply turn it on or off with the push of a button, nothing more. No voodoo with resistors and what not, just an on/off. And if it were feasible, does the VX need to be stopped during the switch in either direction?

If I'm dreaming here, let me know. Not that the invitation is required... :winkgray:

-V

[89Vette]

IF TOD IS TUNED OFF OR THE TOD CONTROLLER IS UNPLUGGED THE REAR WHELLS WILL ONLY DRIVE THE CAR , NO TOD ACTION AT ALL, FOR THE MOST PART THE TOD WHEN WORKING CORRECTLY WILL DO JUST THAT DRIVE THE REAR WHEELS EVEN WHEN TURNED ON EXCEPT IN A CASE WHERE THE REAR WHEELS START TO LOOSE TRACTION AND THEN POWER IS APPLIED TO THE FRT IN PROPORTION TO THE REAR WHEEL SLIPPAGE, I HAVE MANUAL HUBS ON MY 01 WITH THE TOD AND AHVE SAW NO IMPROVEMENT IN MPG NONE AT ALL, , PROB ON A CHASSIS DYNO RUNNING AT A STEADY SPEED YOU MAY SEE A VERY SMALL CHANGE BECAUSE THE FRT WHEELS WOULD NOT BE TURNING THRU THE FRT AXLES AND THE FRT DIFF, I PUT MANUAL HUBS ON MINE TO SAVE THE FRT DRIVE AXLES , AND THE BOOTS , PERFORMANCE , MPG , NO CHANGE WHAT SOEVER , THE TOD DOES NOT WORK UNLESS IT IS CALLED ON AND THEN ONLY BRIEFLY EXCEPT WHEN IN LOW RANGE.

I replied back and asked why there's seems to be extra drag in these full-time 4wd system -- IF -- the description above is totally accurate. I think a 2WD mode would feel more free-wheeling. And, less drag should help with MPGs.