Horn/light switch problem

[Jembow]

I took this '28 RPU apart about 12 yrs ago and I'm finally at the last stages of re-assembly.

Overhauled the Sparton horn, fooled around taking the horn rod out to cleanup the horn button, all works fine -AOOGAH! But when I turn the headlamp switch to main beam the horn goes off.

I have had a meter across the bottom rod terminal to earth and there is no leakage when I turn the light control, even took the switch apart and held the horn connection against the rod terminal - horn works but again no issues when I turn the light control. So logic says, it's not in the column, something is going on in the switch itself.

Any thoughts gratefully received.

 

[alexiskai]

I wonder if it could possibly be up at the top of the horn rod, i.e., something is sticking on the button assembly, such that when you rotate the rod, the contact closes and grounds the horn.

 

[Jembow]

Sorry, forget my original post! I have very carefully done the continuity test between the bottom horn terminal and earth again, in certain positions it WILL earth out so I need to pull the rod and replace the horn wire.