Light 'em up!

After wrapping up another visit to the Providence Cruise-in recently, the lights on my 280z did not behave as expected.  Particularly, the parking lights would behave erratically.  Finagling the switch would cause the lights to flicker so I felt confident that the issue was in the switch itself.  Ironically, one of the reasons I added headlight relays was due to the fact that running full current through the switch would cause them to fail over the years;I guess I passed the point of imminent failure before addressing that issue.

While researching a fix for this common issue, I came across the following article which I used as the basis for my fix: http://www.kamikazeracing.org/dl/ZTech/Rebuild_240Z_combo_switch.pdf

To start, I removed the headlight switch from the steering column.  The bullet connectors for the headlight and parking light wires were buggers to separate and I eventually had to use a small screwdriver to spread the female end of the connector.

In retrospect this process could likely be performed with the switch on the car but having no idea what I was facing I decided that removing the switch would be better for me.

After removing the switch from the steering column I quickly tested the switch with a VOM to confirm high resistance in the contacts.  Both the parking lights and the headlight circuits read almost 200 ohms.  For direct copper-to-copper switches that was very high indeed.

I removed the headlight switch contact casing from the column switch assembly.  This should make it easier to remove the bakelite board and access the switch contacts.

Next was to carefully bend the retaining tabs upward so that the contacts could be accessed.  I did this using a very small flat-head screwdriver followed by some needle-nosed pliers.  Go easy on the tabs since you'll have to bend them back down later!

With the contacts exposed, there was evidence of the high current (and thus high heat) that has run through this switch over the years.  The headlight switch was especially dark on top.

The contact base looked to be in good shape.  I used a small wire brush on a Dremel to clean up any carbon and corrosion that may have existed.

The switch rockers told an interesting story.  Check out the indentation in the headlight switch due to the current load...

 

The above photos were taken after the rockers were cleaned up but they had their share of carbon scoring on them.

At this point I reassembled the switch which is as straightforward as reversing the disassembly.  As mentioned in the reference article, I swapped the two rockers to give a "fresh" contact for each switch (the parking light rocker moved to the the headlight side and vice-versa).  I did use a coat of 3M Dielectric Silicone Grease on the contact points and the plastic, spring-loaded "nubs" to ensure smooth operation and to keep arcing to a minimum.  The result?  The VOM registered less than 10 Ohms for each switch and the switch now operates with smooth perfection!