A65 electrics

[huntingdon]

Hope someone can help.
My 1964 a65 with fully charged battery fitted is showing minus 4 amps on the ammeter when ignition turned on. When ignition turned off no problem. Checked with multi-meter and it is taking about 3.7.
Checked everywhere for a short but all good, with exception of points closed causing the drain on battery. if disconnect the points or manually open them the ammeter stays at zero, so definitely this is the area where short is occurring.
Checked coils and no short, checked charging system and no short, checked rectifier and no short.
Any ideas?
Thanks

[geraldhattrick75]

Any issues with the points capacitors?

[huntingdon]

Not sure about the points/capacitor, need to look on internet to find out how to check. Its a long time since i didn't have electronic ignition
so starting from scratch on this one.

[DAVE BRADY]

Hi,

The ignition will surely draw some current when the points are closed?  With the ignition on slowly turn the engine and see if the ammeter returns to zero and see if the points are open at this point.
I think that what you are seeing is what would be expected.
Also, once running does the ammeter show a charge?

Dave.

[geraldhattrick75]

What is the resistance of the primary side of the coil? That should give you an idea of the the current draw when the points close......

Dave

[LightningAndStarfire]

The ignition coil is something like 3 ohm I believe. Battery 12V gives current 12/3 = 4 ampere. Seems ok. Cheers.

[geraldhattrick75]

Yeah, I've just popped out and checked mine.... 3.4 Ohms, which suggests that the current draw is about right.

Dunno why I didn't think to do that before you mentioned it L&S.....