Mercury Marine Bad switch box?

[mburchart]

Hello. first post here. Thank you to all for the knowledge i have received from this site. Thanks.

down to business. i have a 50 HP 4 Cyl 2 stroke 1985 Merc. S/N 7223907.

I am pretty sure that i have a bad switch box but want to confirm.

when i put a multimeter up to the switch box with the settings for 200V DC test. i get inputs reads on the incoming wires of: 144,73.3 146.7, 74, 14.5 and a couple register zero. the four outputs that go to the coils read zero or sometimes .003

I wanted to make sure this was the problem before i spend the money on a non refundable part.

i think stator is fine. not sure how to test trigger.

Thank you.

 

[reynold460]

Re: Mercury Marine Bad switch box?

do you have a cylinder or cylinders not firing, check for spark first with a spark tester

 

[mburchart]

Re: Mercury Marine Bad switch box?

I am getting zero spark. I was able to hold the spark plug wire in my bare hand and grounded it out and was not getting spark.

also had a spark plug tester that does all four at once. no spark.

multimeter on coil had no reading.

Thank you.

 

[schematic]

Re: Mercury Marine Bad switch box?

I wanted to make sure this was the problem before i spend the money on a non refundable part.

i think stator is fine. not sure how to test trigger.

Thank you.

You will not be able to test the ignition components thoroughly without a DVA or Oscilloscope. Acquire a DVA adapter and go to CDI electronics website to troubleshoot properly.