Ignition switch and graphite - OK or a problem?

[worzella]

Hello all - 

 

My final rebuild items are wrapping up and as some of you might remember, I was having an issue that mysteriously my "L" alternator dash light was staying lit EVEN when the ignition was totally off and key removed. New alt and VR, so could be some other item... but have not been able to get to car to test new VR/alt replacements. 

 

But in studying the issue, I learned that one side of the "L" lamp is connected to alt D+ and the other is connected to +12 when the car is running. Hence any volt difference > ~2 v causes the light to light. But when the car is not running and the key removed, that +12 side should be open with no ability to flow current. But somehow mine is.

 

I have been wracking my brain for ideas and then I remembered that earlier in the day I had squirted a couple puffs of powdered graphite into the ignition cylinder to ease up the motion. I searched FAQ and saw it recommended over the years. But then last night I found out that powdered graphite is indeed a conductor, contrary to what I would have thought. 

 

So my question is... since I have never taken apart the ignition cylinder... is there any way that the graphite powder could have shorted out some of the ignition connections? I am not sure if the mechanical "key" part of the lock cylinder is completely isolated from the electrical portions of the 4 settings of OFF, XXX, RUN and START..

 

Anyway, I was just wondering if there are any ignition lock cylinder experts out there who could comment

 

Randy 

 

 

 

 

 

 

 

[Mike Self]

All I can say is that I've used LockEze (powdered graphite suspended in a solvent that evaporates) over the years in my ignition locks with no problem.

 

Also the path for that graphite to get from the lock cylinder to the electrical portion of the ignition switch is kinda tortuous.  Graphite is a conductor but nothing like copper or other conductive metals, so unless you dumped a whole can of the stuff into your switch, I kinda  doubt that's the cause.

 

IMHO

mike

 

[John76]

The lock cylinder is totally isolated from the ignition switch. Squirting graphite or WD40 into the lock will not find it's way to the electrical contacts.

I suspect your problem is a bad switch. Easy to replace....although a PITA to get to under the dash.

My switch failed due to too much load from dual horns and fog lights. Make sure all "high amp" consumers are routed directly from the battery to relays....NOT through the horn or head light circuits.

[torquewrench80]

What year is your car Randy and is it a tii? A shorted diode in the alternator could cause it to remain light even with the key off, which is usually the case. 

[worzella]

A ‘75... and I suspect that will be the cause but bothers me that the explanation of how “L” is wired doesn’t make sense for any current flow when off and key out

 

But I am probably overthinking things ?

[torquewrench80]

Pull the 3 wire plug at the alternator and the voltage regulator. With the key off see if you have voltage present at the wire that connects to D+, a solid blue wire I believe. If it does, check to see if there is voltage present at the + primary terminal on the ign coil, also with the key off. If D+ it doesn't have voltage, take a standard 12V test light, connect it to the positive side of the battery and touch the probe to the same D+ wire and see if the test light illuminates. Just for fun and maybe to learn something. 

Edited October 20, 2017 by torquewrench80
additional notation.

[worzella]

Thanks. Will add it to my list of trsts. Car is at my brothers and won’t get back to it for a few weeks 

 

Will report back

[02cultcar]

Solex, I wish I was there to help you through this...two simple things to consider now and if you have mysterious starting issues in the future.

 

One: If the engine cranks but won't turn over...try doing it in the dark and look for electrical arcing between cap, wires, and block. It won't start that way.

Two: If the engine cranks but won't turn over inspect the ignition wire to the starter. It gets dry, cracks, arcs, and breaks. Simple fix I should have looked at before considering a broken timing belt.

 

Best of luck on getting it roaring. DK 

[worzella]

Quick up date on my odd "L" light issue where it stays ON even when the ignition is off and key out. I finally got back to the car location and tested a few things. The wiring was OK but when we fired up the car, the "L" light went out as expected, but the alt was not charging the battery. I checked with good multi-meter and my brother even had one of those dedicated testers you hook to battery that shows voltage and a nice color coded dial with red, yellow and green areas. 

 

So despite the fact that no circuit diagram I can find shows the ignition side of the "L" light going to ground when ignition off/key out, it has to be that way and my D+ output of the alt is driving current.

 

I am done trying to figure out the issue and will install new Bosch alt since I think the current one is possessed/broken somehow. 

 

One more update later to let you know if this cleared up all of the issues.

 

Randy