Mercury 402 No Spark

[camaro82]

Hi guys ive got a mercury 402 which died when i was out on the water, thought it was due to trolling for too long but got it home and still wouldnt start. It started once when i tried to start it but only for about a second. Got someone over to check for spark while i was turning it over and there was no spark.

So the tests began
- Checked both coil resistance, tested fine
- Checked mercury tilt switch resistance, tested fine
- Tested stator resistance, tested fine
- Tested the trigger and it shows a resistance value for about half a second then drops back to 1(open?) is this how it is meant to test or should it show the resistance value all the time?

I hope this is the problem and not the box as there is a bit of a price difference from one to the other.

Any suggestions?

 

[Fuzzytbay]

Re: Mercury 402 No Spark

So the tests began
- Checked both coil resistance, tested fine
- Checked mercury tilt switch resistance, tested fine
This should read open?

- Tested stator resistance, tested fine

Did you test for continuity to ground?


- Tested the trigger and it shows a resistance value for about half a second then drops back to 1(open?) is this how it is meant to test or should it show the resistance value all the time?

I hope this is the problem and not the box as there is a bit of a price difference from one to the other.

Any suggestions?

Should be something simple, if it just quit without a bang, at low speed.

 

[Laddies]

Re: Mercury 402 No Spark

If your meter reads 1 when the wires are not connected then the trigger is open ane needs replaceing. The first test should be disconnectint the orange-black/yellow wires from the box and check for spark

 

[camaro82]

Re: Mercury 402 No Spark

Ok removed the orange wire still no spark.

Retested Stator
- Blue to Ground 5200ohms (manual states 5000-6000)
- Red to Ground 47.8ohms (manual states 50-60) a little bit low

Tested Trigger
- Brown to White 820ohms (manual states 800-100)

Also tested coils and they are ok

So im guessing its the Switch Box hey? Ill do the DVA tests on the switch box when ive got another person and then take it from there.

 

[camaro82]

Re: Mercury 402 No Spark

Got it started guys, replaced all of the wires that were getting old and the insulation was starting to get brittle and crack, so they were obviously touching somewhere, and then i thought id just crank it so see if it still cranks and bam within one second it started!