4wd light flashing

[clintnz]

Sorry I don't have many pics of that but the process was very simple, if you have ever successfully installed a relay in a vehicle you should be able to work it out. Just go over the vac solenoids with your multimeter to work out what's what, then install a change over relay switched by the 4wd button to power either vac solenoid. There were a few wires to the switch IIRC but it wasn't difficult to work out.

Cheers
Clint

 

[Omrib]

Sorry I don't have many pics of that but the process was very simple, if you have ever successfully installed a relay in a vehicle you should be able to work it out. Just go over the vac solenoids with your multimeter to work out what's what, then install a change over relay switched by the 4wd button to power either vac solenoid. There were a few wires to the switch IIRC but it wasn't difficult to work out.

Cheers
Clint

Hi Clint
Just a bystander, do not have the same system.
Was wandering if the vacuum solenoids need to be active at all time that vehicle is on, or just when desiring to change transfer position, either way (somewhat momentary, till position is gained).
For example, if the vehicle is shut off and switch is not engaged, transfer should probably retain previously set position.
Logic specify that nothing should be happening while vehicle is shut off, thus implying that the action of changing transfer position is supposed to be momentary and shut off when position is gained or by means of timer with suitable time frame, or by the driver when he sees indication the position of transfer had changed according to whish.
Let me know if I am missing something as I am not familiar with the specific system ECU.

For me, if I had to do it on my vehicle, I would probably use a DPDT M,OFF,M toggle (or rocker) to control the two solenoids, manually by the driver, and use the 4wd light (or the sensor itself directly with a led indicator) as indication to stop activation of desired position.
This way bypassing the ecu completely.
Hope this helps any, or at least does not confuse.
Good luck

 

[clintnz]

Hi Clint
Just a bystander, do not have the same system.
Was wandering if the vacuum solenoids need to be active at all time that vehicle is on, or just when desiring to change transfer position, either way (somewhat momentary, till position is gained).
For example, if the vehicle is shut off and switch is not engaged, transfer should probably retain previously set position.
Logic specify that nothing should be happening while vehicle is shut off, thus implying that the action of changing transfer position is supposed to be momentary and shut off when position is gained or by means of timer with suitable time frame, or by the driver when he sees indication the position of transfer had changed according to whish.
Let me know if I am missing something as I am not familiar with the specific system ECU.

For me, if I had to do it on my vehicle, I would probably use a DPDT M,OFF,M toggle (or rocker) to control the two solenoids, manually by the driver, and use the 4wd light (or the sensor itself directly with a led indicator) as indication to stop activation of desired position.
This way bypassing the ecu completely.
Hope this helps any, or at least does not confuse.
Good luck

The standard system in my LJ71, & I assume other cruisers with the same vac operated split-case transfer case, is that vacuum is continuously applied to the t-case diaphragm to hold it in 2wd/4wd as required.

I don't think there is much of a detent to hold the 2wd/4wd shift mechanism in place otherwise but I could be wrong on that, it's been a while since I had one apart.

Cheers
Clint

 

[Omrib]

The standard system in my LJ71, & I assume other cruisers with the same vac operated split-case transfer case, is that vacuum is continuously applied to the t-case diaphragm to hold it in 2wd/4wd as required.

I don't think there is much of a detent to hold the 2wd/4wd shift mechanism in place otherwise but I could be wrong on that, it's been a while since I had one apart.

Cheers
Clint

That is interesting
So, would it be possible for a parked vehicle to go into neutral (t-case) under certain conditions, while vacuum is no longer existing, if the vehicle was to be rattled or slightly moved?
Or is that something that have never happened (as far as anyone knows) ?

 

[clintnz]

That is interesting
So, would it be possible for a parked vehicle to go into neutral (t-case) under certain conditions, while vacuum is no longer existing, if the vehicle was to be rattled or slightly moved?
Or is that something that have never happened (as far as anyone knows) ?

Having a look at the workshop manual the vac shifted t-case does actually have a detent ball on the shifter mechanism.

Cheers
Clint

 

[Omrib]

Having a look at the workshop manual the vac shifted t-case does actually have a detent ball on the shifter mechanism.

Cheers
Clint

Thank you for taking the time to verify and share the information.
It seems that other than this forum, and maybe one more (machining and vintage machinery), there aren't many places for me to ask questions and take interest in small details that usually do not interest anyone else around me.

It is a kind of a shelter from the narrow minded shallowness overwhelming the internet and other media.

I am not referring to the topics of interest but rather to the depth of knowledge and investment in that interest.

Keep on getting smarter and have fun doing so.
Cheers
Omri