Electrical Gremlins, HELP!!! Options

[richardL]

So my car ran the other day without problems. At first there seemed to be electrical issues, then they miraculously went away and now they are back.

Now its completely dead on the ignition switched circuits.

The car has carbs and hence no FI, most of that wiring is removed.

The battery is charged, the parking lights work and the instrument panel lights come on as well, the green parking light light as well.

I thought there was a problem on the ignition switch, so I have a brand new race style switch. Power in, switched power out, starter out.

With the ignition off I am getting around 13 volts at the switch. When I turn on the switch I get 0 volts. I disconnected all the three output wires (red, black and a thin red, which I think is for the voltmeter) and then I have 13V at the output terminal of the switch. If I connect any one of the three output wires again I get 0V. With them disconnected, if I try the starter, momentary switch the voltage goes to 0V - the starter doesn't try to turn or anything.

I removed all the fuses, just in case, and it has no effect on the above symptoms.

I also have an external kill switch and I always seem to have the expected 13V at the output of that, even when the ignition is switched on and doing nothing.

I am confused, as any kind of connection seems to kill the voltage, yet the battery seems OK and can support side lights at least.

Am I missing something obvious? Am I being dumb? How should I go about diagnosing this? Any suggestions would be very gratefully received.

Richard

[Dr Evil]

Hey Richard,
Let me see if I can understand; when you turn the switch to "on" and measure voltage, are you measureing from the switch to ground or across the switch? The latter should produce a 0V state as the switch should effectively drop 0V. If you are measureing to ground and you get 0V either your switch is bad, or there is a short in the system sucking all of your juice.
The best check to see if your battery is bad is to put the meter across the two terminals of the battery (should be around 13V) then turn the switch. Your voltage should drop a little, but anything around the 9V and below may indicate a proble. Consequently, a short in your system will also present with this symptom. Be careful of a short as there is a possibility of fire.
What realy concerns me is your kill switch. If you are getting a constant 13V at that regardless of your ig switch situation then I would say that is likely your culprit.
Figure it this way:
-If you get volts to your ig switch then all things leading to the ig switch are fine. Not Kill switch if it lies before the ig switch.
-check that you get actuating voltage at your starter (little wire, should be 12V when key is turned). If so then everything to your starter is functioning. you must have 12V, no less or you will have to clean up your start circuit as it is dropping to much voltage.
-you can take a large metal tool of your choice and cross the terminals on the back of the starter to see if it is working (not for the faint of heart, lots of sparks). If the starter turns then your battery is good, and your solinoid may be shorting out.

My guess would be that the kill switch, or the starter solinoid is the problem. If you are droping all of your volts then the solinoid may have an internal short. Start with the simple and go from there.

Sorry for the length, but I was trying to cover every contingency.

Mike