Thread: Wiring harness shot - basic hookup to run a 186 motor

A Neg ground coil grounded to the engine or chassis, a wire going from +ve on the battery to batt on the coil and a wire to the distributor. (and the high tension from the coil to the dissy.)

You can also put a switch in the battery to coil wire so you can turn it off.

After that you start to get fancy with starter swiches and alternator wiring.



Note in the graphic above the coil is a 7volt or 8volt coil and uses a 5V or 4V resistor from the IGN on the starter switch, this is bypassed on start to compensate for the voltage drop when the starter motor is cranking. (The 12V coils suffer badly from voltage drop making for hard starting.)

As per above diagram, but don't concern yourself with the resistor on the coil circuit just for the purpose of seeing if it runs. Just full 12v+ to +side of coil, -side of coil to the breaker points in the distributor and, as long as the timing is somewhere close, you're good to go.

Thanks for the diagram Diana, your knowledge as always is invaluable.

Does the body of the coil also need to be earthed? I have no bracket for it just a loose coil, so does the body form part of the circuit or is it all with the wiring connectors?

yes the coil should be grounded otherwise you don't have a high tension circuit.

Originally Posted by Lotz-A-Landies

yes the coil should be grounded otherwise you don't have a high tension circuit.

Not true, as far as the high voltage low current secondary is concerned the 12V connector or the points condensor is as good as an earth. Using a multi meter, testing a few random coils in my collection reveals no connection to the case.

Originally Posted by bee utey

Not true, as far as the high voltage low current secondary is concerned the 12V connector or the points condensor is as good as an earth. Using a multi meter, testing a few random coils in my collection reveals no connection to the case.

I'll second that.

Dave.