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

[richardL]

The Kill switch is the first thing in line after the battery. The output of the kill switch goes to (among other things) the ig switch.

When I have any wire connected to the output (for instance the black that goes to post 15 on the ig switch usually) the voltage at the input to the switch (measured from the post to ground) drops to zero - as you say I expect a short. The problem I have is where?

When the ig switch seems to be shorted I still have 12.85V at the battery and the same at the kill switch. Yet at the input to the ig switch I have 0V!

If it were in the wiring beyond the ig switch I would expect the starter to turn when I close that part of the switch, but the voltage goes to 0V as well. So I don't know if its the starter solenoid. But if it were I would expect to only see a problem when I try to turn it over. But I lose voltage when the red from post X, the black from post 15 or the starter is energised. Also when i touch the thin red wire that I think goes to the voltmeter.

I have the Haynes manual, and I've been using the Pelican diagrams as well.

As I said, when I first tried to start it a week ago I had these symptoms, then I fidlled with the ig switch and it worked, started and ran fine, all the instruments worked. I turned it off, ran it again a day later, and then when I tried the other day - nothing. I have now put in the new, simpler switch to replace the ignition, and I tested the switch and can see it works.

It has to be a short somewhere, but why does every wire I connect cause the problem. Surely only one should?