Vacuum transfer case 4wd switch operation (2 Viewers)

[RodrigzCrzr]

Hello Everyone
I have been working on my 71 fj40 lately and getting down now to having the exhaust installed. As I am waiting for the day for that. I have been going through all the small electrical items that are not working.
I have come across the 4wd indicator light it comes on when I pull the FD knob out and stays on while in four wheel drive (obviously as it should).
but when I push the FD knob for 2wd it still stays on. I have removed it and checked it while off the transfer case. and it seems like it works as I push the button in and out. So there is continuity when I apply the switch.
My question is is there something that goes in the switch housing of the switch? then the switch.?
does anyone know how it functions?
I have looked up the parts diagram on the Amaya website and I don't see any kind of ball or anything that will plunge the switch to turn off. or is it a magnet?
your feedback and help would be much appreciated.

 

[Living in the Past]

The lamp on the dash has a plastic isolator between the housing and the lamp socket. Lamp socket plugged directly into the housing gives the lamp a ground that suppose to come from the switch on the transfer case.

 

[RodrigzCrzr]

The lamp on the dash has a plastic isolator between the housing and the lamp socket. Lamp socket plugged directly into the housing gives the lamp a ground that suppose to come from the switch on the transfer case.

yes I have cleaned that and have replaced the bulb. but when I shift into 2wd it still stays on. trying to figure out why it stays on?

 

[RodrigzCrzr]

I know it is out of 4wd cause the front drive shaft spins freely.

 

[Living in the Past]

yes I have cleaned that and have replaced the bulb. but when I shift into 2wd it still stays on. trying to figure out why it stays on?

Is there a round black plastic piece that screws on the housing and the socket with the lamp snaps in the black plastic piece?

 

[RodrigzCrzr]

Is there a round black plastic piece that screws on the housing and the socket with the lamp snaps in the black plastic piece?

yes

 

[RodrigzCrzr]

Im wondering if there is a mechanism in the housing where the switch screws into that pushes that switch to off position or a magnet.

 

[Living in the Past]

So the lamp stays lit with in not attached to the housing? If so try unplugging the two wires at the transfer case one at a time and check. My 70 Fj40 the switch was crumbling apart and lamp never lit. One of those wires should be grounded and the other goes to the outside of the lamp socket. The switch completes the ground. These are easy to trouble shoot.

 

[RodrigzCrzr]

So the lamp stays lit with in not attached to the housing? If so try unplugging the two wires at the transfer case one at a time and check. My 70 Fj40 the switch was crumbling apart and lamp never lit. One of those wires should be grounded and the other goes to the outside of the lamp socket. The switch completes the ground. These are easy to

 

[RodrigzCrzr]

ok I will try that.

 

[Living in the Past]

The switch was sold with the complete unit but in parts diagrams it shows up separate under electric

 

[RodrigzCrzr]

So I removed the switch.
1st pic is of the TC in 2wd
2nd pic is if the switch itself
3rd pic is of the TC in 4wd.
I don’t see anything different only that in 4wd the rod looks scratched.

 

[RodrigzCrzr]

The switch was sold with the complete unit but in parts diagrams it shows up separate under electric

Yeah I see that. I think I will order it.
Thanks

 

[Green Bean]

I doubt this will be of any help... If I recall correctly, our switch that goes into the transfer case was toast. I purchased a used switch. When I was diagnosing things, I rigged up a short jumper wire and ran it between the 2 bullet connectors near where the switch goes into the transfer case. The dash light would illuminate with the jumper and go off when the jumper was removed. So I knew the issue was the switch. Replaced the switch and problem solved.
Good luck.

 

[RodrigzCrzr]

I doubt this will be of any help... If I recall correctly, our switch that goes into the transfer case was toast. I purchased a used switch. When I was diagnosing things, I rigged up a short jumper wire and ran it between the 2 bullet connectors near where the switch goes into the transfer case. The dash light would illuminate with the jumper and go off when the jumper was removed. So I knew the issue was the switch. Replaced the switch and problem solved.
Good luck.

I did that same process and it the switch still stays one wetter it is in 4wd or 2wd.
I remove the switch and put a meter with continuity and it works fine on and off.
I think the switch it has now doesn’t reach the rod .

 

[middlecalf]

You say in your first post that when you pull the FD knob the light comes on, and then stays on. How did you get the light off originally?

There’s a depression in the rod 36424 that moves the switch mechanism. I wonder if the rod can be oriented such that the depression is not facing the switch? The earlier TC switch’s (‘63 and ‘65) I believe do have a ball under the switch, but your parts diagram doesn‘t show one. Part O in these diagrams for a ‘65.

With the switch unplugged and connected to wires you should be able to switch the light on and off by depressing the switch button. If the light is on when in 2WD, switch the wires.

 

[RodrigzCrzr]

You say in your first post that when you pull the FD knob the light comes on, and then stays on. How did you get the light off originally?

There’s a depression in the rod 36424 that moves the switch mechanism. I wonder if the rod can be oriented such that the depression is not facing the switch? The earlier TC switch’s (‘63 and ‘65) I believe do have a ball under the switch, but your parts diagram doesn‘t show one. Part O in these diagrams for a ‘65.
View attachment 3028182View attachment 3028181

What I meant to say is the light stays on regardless of the FD knob pushed in or out.
It never shuts off unless I turn the ignition to off.
So do you think possibly I may need that ball to put into the switch housing?

 

[middlecalf]

I think you need a ball, your switch isn’t contacting the rod. But someone with a ‘71 parts manual can verify.

 

[RodrigzCrzr]

I didn’t think it was either.
I have an old detent ball and spring from a 60 series TC.
You think that ball may work?

 

[RodrigzCrzr]

Well after doing some research. I found an exploded view of the diaphragm for the 71 fj40 on the Spector website.
And it shows a detent ball for the that switch.
You where correct @middlecalf and @EWheeler.
Going to order it and see what happens.
Thanks all for your input and help.