stator: resistence perfect, voltage only .5 - what gives?

[JonG@schooner]

On a Mercury 8 HP 2 cycle outboard motor what does it mean if the stator resistence reading is perfect but the AC voltage which should be at least 150 Volts is only .5Volts?

 

[CharlieB]

Re: stator: resistence perfect, voltage only .5 - what gives?

Stator voltage should be measured with a DVA Meter with the stator leads dis-connected from the ignition.

A bad ignition can give a false reading if the module is internally shorted.

Re-test and repost your findings.

Remember, there is NO RETURN on electrical parts so you want to be SURE before ordering ANY parts.

If stator remains low, remove the flywheel and inspect the magnets, any loose, broken, or crack magnets will also cause low stator voltages.

 

[JonG@schooner]

Re: stator: resistence perfect, voltage only .5 - what gives?

CharlieB - thanks for the response - I did the measurments with a DVA meter measuring AC voltage with the leads disconnected from the switch box according to the instructions in the manual. Got .5 volts. The magnets look brand new and there are no cracks. What confuses me is that the resistence is perfect. I don't understnad how I can get perfect resistence if there is a short in the stator module.
Thanks for your help - JonG@schooner

 

[j_martin]

Re: stator: resistence perfect, voltage only .5 - what gives?

CharlieB - thanks for the response - I did the measurments with a DVA meter measuring AC voltage with the leads disconnected from the switch box according to the instructions in the manual. Got .5 volts. The magnets look brand new and there are no cracks. What confuses me is that the resistence is perfect. I don't understnad how I can get perfect resistence if there is a short in the stator module.
Thanks for your help - JonG@schooner

If there's 100 turns in a coil, and a single turn is shorted out, it will have very low output, and the resistance will only be 1% low.

Now you know why the DVA test is so important.

hope it helps
John

 

[JonG@schooner]

Re: stator: resistence perfect, voltage only .5 - what gives?

j_martin - Thank you - this is very helpful.

 

[verado7]

Re: stator: resistence perfect, voltage only .5 - what gives?

yep resistance test is easy to do and can find problems easy- but in the end dva output tells all -