90 hp mercy no spark

[Imarudedude]

Hello all. I have a 1993 90 hp Mercury outboard (serial # 0d179573) that is having some issues.

The current situation is that it is not getting spark. The motor was running perfect with no issues. Two things happened and I'm not sure which one or either is the problem. The motor ran out of oil, their was no low oil or overheat horn connected to the engine sensor.

The second is that I started going through the wiring because it is a mess. At some point the previous owner added a different ignition with a kill switch.

I was just trying to get the gas gauge to work because it wasn't working. Well I have the gauge working (woopty freaking do) but I no longer have spark.

The power tilt and trim work. It is also turning over and getting gas but no spark.

I used a multimeter to check the terminals on the ignition and it appears to be working properly.

I'm not sure what the problem is or where I would start my troubleshooting. Any help would be very much appreciated. Thanks in advance

 

[Imarudedude]

I also tried to upload a picture of the voltage regulator/rectifier because it appears to have a black substance oozing out of it. I'm sure it's not a good thing.

 

[Texasmark]

Go to the trigger CDI modules....the 3 black things with the spark plug wires sticking out of them. Pull the connector to any of them and get on the yellow with black stripe wir (connector pin) with an ohm meter that goes back to the external wiring harness and on to the control box. Measure the ohms between that pin (wire) and battery -. If you have a short you have your smoking gun. That wire is the trigger ground wire that shuts down the triggers when the ignition is off or the kill switch is killed. It is supposed to be open circuited when you want to run the engine.

 

[Imarudedude]

Thanks for the response Texas I really appreciate it. I've been working crazy hours lately so I haven't had a chance to get back into anything.

I'm a little confused about your reply though. Are you telling me I should check continuity between the yellow/black wire from the CSI trigger box and ground?

 

[Texasmark]

Yes with the ignition switch in the off and on position. It should be an open circuit when in the on position and short to ground when in the off position. If you have continuity when in the on position, the switch is surely the culprit due to metallic contamination internally from too many ons and offs over the years.

 

[Imarudedude]

Thanks for the help Texas got it all straightened out! I switched out the switch box and the voltage regulator. Was on it all day today with no problems!

 

[Texasmark]

Great