Rectifier test

Dear Forum, I read on CDI's website that to check my rectifier for my 9 amp charging system I disconnect the two yellow wires from the stator and see if I have spark then??? My problem is I have lost spark to all three cylinders as I noted in a previous post. I checked the red and blue wire from the stator to the switch box and the blue wire tested bad as well as my test between the red and blue wire, the blue wire tested bad from the wire to ground is what I meant first. If these two wires test bad is it even worth checkin the two yellow wires from the stator to the rectifier? I have removed the rectifier completely and checked it and it all checked good. I put it back in and I still have NO spark, so, as I asked, does it pay to remove the two yellow wires from the rectifier and see if I have spark then?? I have been using a spark tester I bought at Advanced Auto.

Re: Rectifier test

if the two wires check bad....your stator is open circuit. The yellow wires are irrelevant at this point...


Replace stator

Re: Rectifier test

Thank you schematic, the blue and red wires feed to the switchbox, I checked them to each other and each one to ground, to ground the red wire was within specs and the blue wire was open, the wires were open to each other also so this means the stator is bad? what do these two wires do going to the switchbox?

Re: Rectifier test

I also checked the trigger wires to ground and got an open, when I checked them to the blk/white wire I go around 1260 ohms on each of the three trigger wires going to the switchbox. Of course I disconnected all the wires from the switchbox before testing. My question to you is, would you go ahead and replace the trigger, I really dont want to spend a ton of money if I dont have to, the stator will be enough. Also, how do I check the switchbox to make sure it is operating fine if I am unable to run the motor? Imparticularly the wires from the coils(3) to the switchbox? Do I need to check these? I have a digital multimeter as well as an old simpson analog meter to use.

Re: Rectifier test

do you have a dva tester try doing this test following the instructions on each color wire while cranking the engine, I found that some times you think you got a good ohm reading, and still it dont work and a dva test tells a complete different answer. resistance is one thing but what the stator, coils, and trigger are putting out when the engine is being cranked or running is totally a different thing try it hope it helps. P.S. be carefull because it is very high voltage 280 volts plus.

Re: Rectifier test

circle hook said:

I found that some times you think you got a good ohm reading, and still it dont work and a dva test tells a complete different answer.

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Agreed...but when you have a bad resistance check, as he does on the stator, a DVA reading can be misleading. Open circuit = replace stator

My question to you is, would you go ahead and replace the trigger

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Hell no, it checks OK as per below link....

http://www.cdielectronics.com/downloads/troubleshooting guide/Mercury 3 Cylinder.pdf