ignition coil - ground

[billydave]

I am somewhat confused about the - and + connections to the ignition coil on my 73 GT. the negative side has two wires, one is connected to the distributor the other disapears into the harness. The positive side has two wires, one is clear(the resistor) and one black which disapears into the harness. There is what appears to be a factory green wire that is grounded to the body but is connected to the positive terminal on the coil. Can this be right? seems like it should go to the negative terminal. Wiring diagrams don't seem to indicate this ground wire. Can't get fire to the plugs. Any suggestions?

thanks

Dave

[gr_diver]

There should be two wires on the + side as you mention, one clear (the resistor cable) that provides ~+9V during running, and one that goes to the starter solenoid, to provide +12V during cranking.

There should also be two wires on the - side, one going to the distributor, and one is going to the tachometer on the dash.

The green wire you mention on the + side sure enough shorts the coil's feed current, thus you don't get a spark. There should be no direct contact to chassis or any grounded parts at neither side of the coil!

[billydave]

gr_diver

I appreciate your response. Any idea what the factory ground to the coil was for and why it apparently did work at one time? Have I caused any damage by disconnecting it?

Dave

[baronbors]

Originally Posted by billydave gr_diver I appreciate your response. Any idea what the factory ground to the coil was for and why it apparently did work at one time? Have I caused any damage by disconnecting it? Dave

Emergency shutoff ????? Probably should replace the coil just be on the safe side.

[gr_diver]

The only thing I can think of, is if someone had wired in a capacitor, between the + side of the coil and ground, to eliminate noise in the stereo....

Or maybe, there was an external ballast resistor that at sometime got removed, and the wire wasn't removed, so someone thought it should go to ground (since there was nothing else around).

Usually opel wiring has two colors on the insulation, one for the most area, and one like a line. How is this wire colored (except for the green)...

Anyway, I do not have a wiring schematic for the GT, but in my Ascona none of the two cables going to the + side of the coil are fused, so please check their condition, and also if there are any fuses that might have blown!

HTH