1974 85 Johnson need some direction

[Donny74]

I just got this boat and motor. It had been stored since 1995. It seems to have a short some where.The rectifier had a naked wire and was shorting out.I fixed that and now it seems to have another. It is only showing a short when the rectfier is hooked up and mounted back on the engine block..Im thinking it is the alternator or the stator..but im new to this.

 

[Joe Reeves]

Re: 1974 85 Johnson need some direction

Donny.... If the short exists only when the rectifier is connected, the rectifier is shorted internally. Replace it.

 

[Donny74]

Re: 1974 85 Johnson need some direction

Thanks Joe,Since I have posted this.Ihace gotten a manual and cheaked the rectifer like it said and it was bad.Is all OMC rectifiers the same because a marine place has one for $41.00 and Overtons have it for $21.00

 

[Joe Reeves]

Re: 1974 85 Johnson need some direction

Donny.... There are various type of rectifiers, three wire types, four wire types, water cooled, etc. You simply need the three wire type which is no doubt the same at both places you mention. Purchase the $21.00 rectifier.<br /><br />Note... Make sure that the polarity at the terminal strip (where the rectifier RED wire will be attached), reads "Positive" (+) on a volt meter before connecting that rectifier wire. A rectifier will not tolerate reverse polarity for a second!

 

[Donny74]

Re: 1974 85 Johnson need some direction

Joe,<br />Thanks alot will get one on Monday or order it tonight. Hopefully I will be on the water soon..

 

[Arrythmic_Mike]

Re: 1974 85 Johnson need some direction

how do you test a rectifier????

 

[Joe Reeves]

Re: 1974 85 Johnson need some direction

Mike.... Check a 3 or 4 wire rectifier as follows.<br /><br />(Small Rectifier Test)<br /> <br />Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction. <br /><br />Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other. <br /><br />Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires. <br /><br />Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier.