Headlight switch problem- 1978 280z

[gotham22]

I was having issues with my headlights where they would only turn on if I played with the knob and moved it back and forth in small increments. I took apart the switch and cleaned up the corrosion. One of my springs with the plastic tips that push the rockers looks melted or worn.  I am assuming this is no longer a part I can get.  Do I need the plastic piece on top of the spring or can I use the spring without it?  Is there anything I can swap the plastic piece with that could work as a fix?

[SteveJ]

Yep, that's a problem. It melts down/wears down because of the heat from all of the current flowing through the switch. Don't try to get a 3D printed version. It will only melt down faster than the original piece.

@Captain Obvious You're better with plastics than I am. Can you think of a hard plastic that could be drilled/milled/lathed into a replacement?

[SteveJ]

@gotham22Do you have a micrometer that you could measure the dimensions of the tab in better condition?

[gotham22]

@SteveJ I have digital calipers

[SteveJ]

So tell us the OD and height. My mind is formulating evil plans as we type!

[gotham22]

OD 3.8mm

H 5.1mm

Edited August 17, 2022 by gotham22
go the dimensions

[Captain Obvious]

1 hour ago, SteveJ said:

 Can you think of a hard plastic that could be drilled/milled/lathed into a replacement?

Nylon 6/6 would be my first choice with Delrin being a close second. Both are easy to machine at that scale, but I think the Nylon is a little stiffer and stronger.

[gotham22]

i have access to a 3d printer.  Do you think that might work?

 

[BoldUlysses]

1 hour ago, SteveJ said:

Don't try to get a 3D printed version. It will only melt down faster than the original piece.

What if you relay the headlights and reduce the current/heat through the switch (which is good practice anyway)?  That would presumably open up more material options.

[cgsheen1]

15 minutes ago, BoldUlysses said:

What if you relay the headlights and reduce the current/heat through the switch (which is good practice anyway)?  That would presumably open up more material options.

That's generally always a good idea.

If someone comes up with a replacement for that plastic tip, I can fix 2 or 3 headlight switches that I have.

[SteveJ]

15 minutes ago, BoldUlysses said:

What if you relay the headlights and reduce the current/heat through the switch (which is good practice anyway)?  That would presumably open up more material options.

It's possible. The problem with most relay installations is that the owner hacks into the wiring. Now, @Captain Obvious provided me key information that would allow a relay kit to be created for the 78 that does not involve cutting any wires and could essentially be tucked away nicely. Unfortunately I don't have an unmolested 78 at my disposal to see that scheme to fruition.

[BoldUlysses]

It's a shame the 240Z relay kit doesn't work for the 280.  I wonder how different it is?

https://www.thezstore.com/page/TZS/PROD/classic10d23/12-4651

I have the parking light relay kit installed on my 240 and it was totally plug-and-play and reversible.

Edited August 17, 2022 by BoldUlysses