Possible Short?

[MGG]

Scenario: 1934 BB truck with helmet distributor, short dome coil, Vertex .36 mfd condenser from Bubba. When I turn on the ignition switch only, the ammeter immediately shows a 4-5 amp discharge. I unhooked the wire from the switch at the coil and there is no discharge when turning on the switch. Am I looking at a short in the distributor or coil? Thanks

[40cpe]

If I understand your issue correctly, your coil is grounded through the points when they are closed. When open there will be no drain on the ignition wire. To verify, bump the engine over until the points open and the drain should go away.

[MGG]

I took off the distributor and cleaned it up and set the points. It runs a lot smoother now and I no longer have the discharge when I turn on the ignition switch. Thanks for the help.

[koates]

Hi there, If the distributer contacts are closed and the ignition ON but engine not running then 4 amps is about normal coil draw for a 6 volt system. If you had a real short then the ammeter would show a full discharge off the end of the dial. Regards, Kevin.

[MGG]

The points were somewhat dirty when I pulled the distributor. Before I pulled it I did kick the engine over with the starter a couple of times but the 4-5 amp draw was still there. Could the dirty points have been acting like they were closed or was it just a coincidence that they did stop in the closed position each time?

[rotorwrench]

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It can sometimes be difficult to get the engine to stop with the points open. The engine has to stop on a compression stroke somewhere close to a TDC and it usually resists that a bit.