Switchbox Testing ?

[StratosRob]

Does anyone know how to test a switchbox. The engine is a 1978 mercury 150V
Thanks

 

[Laddies]

Re: Switchbox Testing ?

There is not really a switch box test but with a DVA you can test input and output to tell if it's working. Also on a V/6 you can switch wires on the boxes to test

 

[StratosRob]

Re: Switchbox Testing ?

What should the voltage be coming from the stator to the box. Also what kind of voltage should be coming out of the box to the coils.Thanks

 

[Laddies]

Re: Switchbox Testing ?

Low speed windings-blue/blue white=150+ volts
High speed windings-red/red white==20+ volts
Out put to coils== 150+ volts
Trigger wires== 4+ volts

 

[StratosRob]

Re: Switchbox Testing ?

Thanks< I'm use to johnson/Evinrude This is for a friend that had this motor just given to him. Compression is 120 even in all cylinders.(good for the year)He dosent want to put a whole lot of money in it. Just in case it knocks or something. Any Idea where i can get a wiring diagram online. Also the switchboxes were in the boat not on the motor. So we are starting from scratch.I told him top go buy a manual Thanks

 

[j_martin]

Re: Switchbox Testing ?

Go get a manual for the engine. The CD rom manuals available on E-bay are ok for general trouleshooting. They are scan grabs, so the pictures tend to be a little fuzzy, but they usually have a wide variety of diagrams in them so you can match your engine pretty close.

One thing, the voltage measurements on a Merc engine are made with a peak reading voltmeter. A regular radio shack multimeter will read way low without a special adapter.

hope it helps
John