reverse light switch problem

[x-unimog404]

On my '73 FJ-40, when shifter is put into reverse, the fuse blows. With the switch removed from the housing, and a new fuse installed, depressing the plunger will activate the light.A soon as the switch is touched to a ground, blows the fuse.
Checking the switch itself with a meter, with the switch out, depressing the plunger will give a 12 volt reading on the casing.
The hosing where the swith screws into is aluminum, so it should not ground the switch??
When the shifter is put into reverse, it throws a rod against the switch and pushes in the contact, which should activate the switch. Since these two parts are metal, when they touch it sends current through and pops the fuse????
Is there an o-ring that goes between the switch and the housing, or the plunger and the rod?? I am not the best at electrical problems, and this has me goin goofy!!!
Any suggestions???

 

[Dave E]

My guess is that the switch has an internal short. If it has been working in the past, and this is a new problem, replace the switch.

Dave

 

[x-unimog404]

That was/is my quess also. Since I have been restoring this for over a year and a half and it was not running when I bought it, I dont knbow if it was working or not. I dont even remember if it was plugged in when I started to take everything apart. Anyone have an exrta switch? That little bugger is about $50 bucks!!

 

[Dave E]

You might talk to your local auto parts store, they may have something you can adapt. (I dont mean autozone or shucks or that type)

Dave

 

[hammerhead]

Check to see if toy-minis use the same switch. I'm not sure but I think they do.

 

[Bailey]

If switch has two leads ...
If you can remove the switch from the trans. then push "reverse" plunger and you get the reverse lights without blowing fuse then you have a switch that is shorted to ground through your trans. (aluminum will conducted power to ground), if fuse still blows with switch removed from case, the short is somewhere else down line. You can also double checks your switch with a meter as follows... check for resistance from power input connection to switch case - should read "open", check resistance from power output connection to switch case - should read "open". press plunger check for resistance from either connenction to case - should read "open" and lastly read connector to connector should read closed.

If switch has only one connection (which I don't think it does)..
Then the case should be your ground and your short is farther back up stream.