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Tan
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10620
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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I have a 1996 mercury 25 hp electric start. It has no spark.

Customer Question

I have a 1996 mercury 25 hp electric start. It has no spark. I replaced the switchbox and still no spark. I was told it was the trigger. Is there a way to test the switchbox and the trigger?
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Submitted: 4 months ago.
Category: Boat
Expert:  Tan replied 4 months ago.

Hello. My name is Tan.

We can do some tests but only on the stator and the trigger. Their is no test for the switch box.

Now have you eliminated the stop circuit? Disconnect the black/yellow wire from the switch box now check for spark. Do you have spark?

Do you have an ohm meter or a DVA peak reading adapter?

Customer: replied 4 months ago.
I have disconnected the the black/yellow wire. I have an ohm meter
Expert:  Tan replied 4 months ago.

Could I get your engine serial number please?

Customer: replied 4 months ago.
1996 mercury 25 hp el 0G290321
Expert:  Tan replied 4 months ago.

Ok we can have 2 different stators. Look at the wires coming from under the flywheel what color are the wires coming out of the stator?

Customer: replied 4 months ago.
red, black, blue
Expert:  Tan replied 4 months ago.

Ok great test between the blue and black you should have a spec of 2900-3500 ohms and the red and black you should have 100-180 ohms..

Then on the trigger test between the brown and white you should have(###) ###-####ohms.

Post back with findings.

Customer: replied 4 months ago.
I can't check today. I will check tomorrow. If they are not with in those readings, does that mean that part is bad?
Customer: replied 4 months ago.
The flywheel is off. Does it have to be on to check the trigger and stator?
Expert:  Tan replied 4 months ago.

Not for the ohm test.

Yes now ohm reading can be wrong when they read in spec. It can be in spec and not work correctly. Now if it is out of spec the component is bad.

If both are in spec then we have to use a DVA adapter to check voltage out put when cranking.

Here is a link to DVA adapters. On the right of this page is a list of suppliers for the 640 DVA peak reading voltage adapter.

https://www.google.com/webhp?sourceid=navclient&ie=UTF-8&gws_rd=ssl#q=peak+reading+dva+voltage+adapter

Post back with findings.

Customer: replied 4 months ago.
I will. Thank you!
Expert:  Tan replied 4 months ago.

Your welcome...........Thank you......Tan

Talk to you later.

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