73 Starter solenoid contact ring coating

[Steve L.]

If you look at the attachment, you can see the gray material that is on most of the surface(underneath,sides and on top) except for an exposed copper ring where the main Battery contacts.

They gray material is an insulator. Placing an ohm meter across this material shows no contact what so ever. But this is where the "R"terminal is supposed to contact. Needless to say that I don't get 12V on the R terminal with the solenoid engergized. Which is why I took this solenoid apart once again.

Anyone know what "plating", if any is supposed to be on the contact ring or what this material is? I'm guessing it is corrosion. But I thought I'd ask first before I Dremel wire wheel this stuff off.

[Stephen L.]

Re: 73 Starter solenoid contact ring coating

Steve, I can't expand your photo so I can't see the ring. If you are talking about the round flat copper ring that moves when the solenoid is energized, it should be completely conductive. This ring is designed to move in a circular motion to distribute the wear from the arc when the starter is engaged. It should also be clean of any debris and corrosion. Clean it off and you should be good to go.

[Steve L.]

Re: 73 Starter solenoid contact ring coating

I reposted the picture

[Stephen L.]

Re: 73 Starter solenoid contact ring coating

That disc definitely should be completely clean copper and also the contacts.

[John P.]

Re: 73 Starter solenoid contact ring coating

The contact disc could have been copper or cadmium plated copper.It should conduct either way.If it doesnt,you have corrosion and it should be cleaned off.

[Steve L.]

Re: 73 Starter solenoid contact ring coating

I was actuallly wondering if it was cad plated and what I'm seeing is cad corrosion. I'm not familiar with what cad corrosion looks like. This coating is really hard- I can't get through it using sharp multimeter points and the ohm meter doesn't show any continuity.

I'll assume it's cad corrosion then dremel wire wheel it gently to see if I can get through the corrosion.

Otherwise, I'll go right down to the copper.

Thanks all