Rectifier problem????

[5150abf]

Trying to trouble shoot a tach problem, checked rectifier while attached to engine, reads ohms both ways, pulled rec off engine only reads one way.

So is it good or bad, when it is grounded to engine it is bad but if you take the engine ground away with all the other wires hooked up it works as it should.

I am mildly retarded when it comes to electrical so any help is appreciated.

Don't know if this is related but the motor mysteriously won't shut off with the key, all I did to create this mystery was I pulled the big red plug apart to check connections and the pin for the grey wire was sticking in the wrong side of the plug(pulled off wire) so I jumped that wire around big red and now the motor won't shut off with the key even with the grey wire disconnected but otherwise runs better than ever.

Key switch is less than 2 weeks old and worked fine last trip.

 

[Randyg123]

Re: Rectifier problem????

You didn't mention what engine/year

Re-check all the connections on your switch to make sure they are tight.
It sounds like your kill wire is not corrected correctly or the new switch is bad. The kill wire is probably black/yellow wire that connects to the "M" terminal.
The grey wire is typically your tach wire
Is there a problem with any other wire at that big red plug?

 

[Vic.S]

Re: Rectifier problem????

You must disconnect the rectifier before testing it. If you are using a digital multimeter use the diode test range rather than the ohms ranges as some meters will not give a low forward reading on the ohms ranges. You wont get a zero forward reading but at least you'll see a big difference backwards vs forwards on the diodes.

 

[5150abf]

Re: Rectifier problem????

81 50 evinrude and all the wires are soldered to the new switch, as I said it worked fine for 2 trips then I pulled big red, yes the arrows are lined up.

The switch was actually for a Honda engine but has all the correct terminals and push to choke.

All other wires looked fine.

I am mostly concerned with the rectifier right now, just checked my old one and it does the same thing, works until you ground it to the boat then I have readings both ways, should that be isolated from the engine ground?

 

[CharlieB]

Re: Rectifier problem????

You have two seperate problems

1 The rectifier must be tested OFF the motor

2 The kill wire terminal in the red cannon plug may not be good, use an exacto knife and very carefully just barely open the slit in the male pins of the plug, use your ohms meter and check the kill wire to the engine block key ON and again key OFF. It should ground to kill the motor

 

[5150abf]

Re: Rectifier problem????

Thank you, now off to the other problem.
I'm sure it is in the plug because everything was fine till I pulled it apart.

As I said elctrical is my weak spot, but off we go.

Kinda stinks cause the motor has never run better.

 

[5150abf]

Re: Rectifier problem????

Ya, it was something in that plug, it turns on/off now but my tach still doesn't work, thanks.

Gotta go to a bunch of graduations the rest of the day so I will hit again in the morning.