Ignition Woes!

[Wcrowder]

I posted about one month ago that I had accidently reversed the polarity while placing a new battery in my 1975 911S. Since that time, I have replaced the alternator and ingnition coil. I still appear to have no spark!! While working on this latest project, I see some wires that are disconnected. I am wondering where these should go and wish that someone could offer some help before I invest in a new ignition control unit or worse, have the car taken to the dealer here. This picture shows my unit taken out of the car, but with the wires where they were! The red wire was not connected to anything! The second picture shows my coil. It was put in with the same configuration and before. Should both sides be grounded to the fan housing?? I am truly lost and any help would be much appreciated!

[Wcrowder]

I don't think the pictures were working properly from my web site. Here they are again! Thanks!

[HawgRyder]

Both sides of the coil should NOT be grounded!!
One side goes to the amplifier (silver box) and the other side is grounded.
If you ground both sides...definately no spark...also...maybe kill the amplifier, since you are grounding the output.

[Early_S_Man]

Is that one of the 'new' Brazilian-made Bosch coils with the 0.221.121.001 part number ... with the bare aluminum case? I have heard of them, but have never seen one in person.

No, both sides of the coil should NOT be grounded ... that would explain one possible reason for no spark!

The #1 terminal of the coil should be grounded. The 'A' or #15 terminal should be connected to the 'A' terminal of the CDI-unit via a White wire. Does the CDI-unit whine or whistle when the ignition key is turned on?

My next suggestion is to remove the CDI-unit, and coil from the car. and set up a bench test using the following diagram to wire up your components. For a trigger lead to replace the points, a simple wire with end stripped can be touched to ground momentarily to generate pulses. To connect a load for the coil output use a new sparkplug and an ignition lead ... with a good grond connection to the spark plug body. If the CDI-unit does not whine or whistle when connected to +12 Volt power, it should be considered defective.

In the diagram below, unit #3 is the CDI unit, and #6 is the coil, with terminal #15 replacing terminal #A on later coils.

[Wcrowder]

I am certain that power is getting to the control unit. I have tested that today. Sadly, there is no noise coming from the unit when the power is applied. Would a perma-tune replacement w/o coil work or should I try to find an original. Thanks much for your time and interest!

[marcesq]

Perma-tune makes a box for your car. New Bosch $1,200.00.(oops try 2,000.00). New perma-tune $275.00.

I have a perma-tune that is 15 years old, still ticking. You might want to search the old posts as I seem to remember that people were saying that permatune was having quality control problems.

Good luck.