Problem after installing electronic ignition

[zellerj]

Today I installed the Pertronix electronic ignition module that I purchased from Moyer marine. All went fine with the installation and my trusty late model atomic four started right up. After a few minutes, I turned off the engine after noticing that the tach was not working - I forgot to attach the tach wire to the coil. I reattached the tack wire to the negative terminal of the coil, and went back to restart the engine and nothing happened - not even a click of the solenoid. A purple wire (catalina 30, 1982) that runs from the ignition switch to the coil became hot and started to smoke. I checked all connections to the started solenoid, switch, and coil to no avail. Not even clicking when I turn the key. I left the boat for a few hours, came back and turned the key briefly, and to my surprise it turned over. Another turn of the key and nothing again.

I took a short piece of wire and jumped the two wires that lead to the solenoid, at the switch, and it turned over. Thinking now that the switch was bad, replaced it, and there was no difference - no click with the key and it would turn the starter with the jumper wire at the switch.

I took out the electronic module and reinstalled the points and condenser. It still would not turn over - not even a click. I can't figure out how the starting circuit and the coil/points or coil/igniter circuit are related in a way that replacing one would prevent the starter from turning over.

Some questions: where does one find a ballast resister - I don't know if I have one or not. Assumed that I did not since I did not find it near the coil.

Would a mismatched coil - 2.0 ohms across the + and - terminal, cause this.

Would a burned out coil prevent the starter from engaging?

Batteries are strong and the boat ran like a champ before today.


Thanks for your help.

Jim Zeller
1981 Catalina 30 TRBS

[Don Moyer]

Jim,

The fact that the purple ignition lead began to smoke after you reconnected the tachometer lead (and presumably not before) would suggest to me that the tachometer lead, or at least what you're reporting as the tachometer lead, is somehow the culprit. When the purple lead shorts out at the coil, the effects of the short would work back upstream to where the power originates, which is from the large battery cable on the starter solenoid.

The heat that you're describing in the wire is also indicative of a very complete short which may mean that you got the tachometer wire on the positive terminal of the coil instead of the negative terminal. If this turns out to be the case, I don't hold out much hope for the condition of your tachometer.

NOTE: The purple lead is usually a 12 gauge wire, and for a 12 gauge wire to become hot enough to smoke suggests that there is no 20 amp fuse in the
ignition circuit.

I would start by removing the tachometer lead, then with the ignition switch on, use a small voltmeter to determine where you have power and where you don't. This process should enable you to determine where your problem is.

The fact that your starter works every time you short between the large battery cable and the "S" terminal directly below suggests that the starter is OK. You're apparently not getting 12 volts to the "S" terminal in the normal way (through your starter switch).

As a separate matter, the 2 ohms that you're reading across the primary terminal of your coil indicates that it is a coil that would normally require an external ballast resistor. Absent a ballast resistor, the coil would have been operating a much hotter than normal temperature (presumably all of its life) and I'm not sure that you ought to be trusting it. To keep things simple, I recommend that you replace the coil with an internally resisted coil. An internally resisted coil will have a minimum of 3 ohms resistance in the primary circuit and be much friendlier to your Ignitor.

Regards,

Don

[zellerj]

New Information

Thanks Don, for the answer and the telephone conversation. For the sake of others, a continuation of this discussion:

After replacing the burned out purple wire that leads from the IGN switch terminal to the + coil terminal, the starter did not turn over after turning the ignition key. Upon removing the new wire, the key would activate the starter moter but the engine would not start. This seemed to be consistent after a number of tries. That is when I called Don. Don suggested that the problem is in the tach wire connected to the (-) post of the coil. I removed the tach wire at the coil, reconnected the new purple wire to the + terminal of the coil, and viola, it started and ran great. I check the continuity of the supposed tach wire at the (-) terminal at the tachometer and indeed it was continuous with the wire I installed on the (-) post of the coil.

And so for now, the engine starts and runs, the points and condenser are installed, and I do not have a tachometer that works. Does anybody have a reason why the tach wire, when connected to the (-) terminal of the coil would prevent the ignition key from activating the starter motor?

Before I reinstall the igniter, I will buy an internally resisted coil from Moyer Marine. I should also insert a 20 amp fuse in the new purple wire.

Thanks Don and any further thoughts are appreciated.

Jim Zeller

[zellerj]

I was at the boat today, and it started right up, as expected. I asked my daughter to watch the tach guage and let me know if it moved when I touched the tach wire to the (-) post of the coil. She said that it did. I turned off the engine, connected the tach wire to the coil, and turned the key. The engine started and ran great and the tach registered. This is inconsistent with my second post, but I am not complaining. After the new coil comes in, I will exchange my externally resisted coil with the new internally resisted coil, and install my electronic ignition module. Hope all goes fine.

I am a chemist, and the one thing that drives you crazy in chemistry is experiments that are inconsistent with what you expect. The results are not reproducible. Sometimes you never find out the reason why, even though there has to be an explanation.

I am finding out that the same is true in engine repair. Frustrating.

Jim Zeller
Catalina 30, 1982

[Don Moyer]

Jim,

I don't recall noticing this fact previously (unless it came up in our telephone conversation), but as I read your previous postings, I notice that you have a Catalina 30. Catalina 30's have a long wiring harness with three Medallion quick disconnects. The quick disconnects at each end are easy to find and check, but the center quick disconnect is in the center of the harness and lies under the sole of the cabin about where you stand to use the galley sink.

When I finally found that middle disconnect on our own Catalina 30, it was lying in a puddle of bilge water and all eight pins were heavily corroded.

On the assumption that your reported electrical inconsistencies are related to a loose connection(s), I would check all the quick disconnects in your harness and particularly the one under the cabin sole.

Regards,

Don