4x4 enganged dummy light

[Justin Fleming]

Is it common for this sensor to fail. Out of no where the light will come on faintly almost as it is grounded out. I have pulled all the wiring up into the truck and I do not see any shorts or issues. I unplug the connector light goes out, If I short the connector accross with a paper clip the dummy light comes on strong as it should not faintly....

Any idea

Also is this just a scrw in type sensor any thing I need to be aware of?

thanks

 

[Fordum]

To be honest, I don't think I have ever worked on one. But I doubt its any kind of a sensor. It should be just a switch that something turns on when you engage 4wd. If there is not a lot of crud between the contacts where you plug the wire in, then something is causing resistance between the switch contacts.

I assume its screwed or somehow mounted to the transfer case housing with the activation part inside.
If so, you might want to check your fluid. The only thing I could think of that would cause that would be if you had some water in the oil and it was causing conduction across the switch contacts.

Or you have a LOT of wear particles in the oil. I had a front output shaft bearing going out on a 205 one time, and the oil was black.
I put some in a jar, and the black part would settle out or move to the side of the jar when I placed a strong magnet there.

I bet it would have been conductive too.....

 

[Chevy305]

The switch is just a button that screws into the top of the tcase. They go bad with age. An easy/cheap replacement.

 

[paratrooper307]

Yep, just a simple switch. You can get em from Rock Auto, or probably the local auto parts stores. Never hurts to poke around and make sure your grounds are good while you're working on it.

 

[Justin Fleming]

so after some additioanl driving and trouble shooting it appears when the light comes on faintly, all I have to do is reach down and pull it in the 4x4 and then push it back into 2wd and the light goes off for a period of time. This was very repeatable so I am leaning towards the switch being bad....