Logo

'1989 johnson 28hp not charging

Re: '89 johnson 28 not charging

(Small Rectifier Description & Location)
(J. Reeves)

On most 2,3,4,6 cylinder engines, the small rectifier is located on the starboard (right) side of the engine just in front of the engines electrical wiring strip. There are a few older V4 engines that have the wiring strip on the rear portion of the engine and the rectifier would be located just under that terminal strip. The smaller horsepower engines usually have the rectifier located on the starboard side of the powerhead close to the carburetor area.

The rectifier appears to be a round object approximately one inch (1") in diameter and also about one inch (1") high. The base of it is sort of triangular in appearance and is attached to the engine with two (2) screws/bolts..... usually one screw/bolt is larger than the other. The rectifier, depending on which one your engine uses, will have either:

One Red wire, one Yellow wire, and one Yellow/Gray wire, or One Red wire, and two Yellow wires.

Note that either of the above rectifiers could have a fourth wire which would be Yellow/Blue


********************
(Small Rectifier Test)
(J. Reeves)

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 fourth 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.

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.

Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.
 
Re: '89 johnson 28 not charging

J.,
I found the rectifier (just like your description) and will remove and test it tommorow. The local parts place has one for $50.00 Thanks again for the Help.
Ron
 
I also have charging problems so I decided to check the rectifier of which appears to be Okay.

I had marked the yellow wires before separating from the terminal block to make sure I connected those back together properly but didn't realize there was also a grey'ish wire in the mix (that was coming from the engine with the red wire).

I'm not sure now where to connect that grey(slightly yellowed) to?

Any help would be much appreciated. Thnx.
 
Effer... This thread is roughly 10 years old. To continue properly, start your own thread/post to have complete coverage.

However, to answer your present question.... a "gray" wire, if it is indeed "gray" that is the tachometer feed that leads to the tachometer "S" (sensor) terminal. At the terminal strip at the engine, it attaches to the stator yellow wire that has the gray stripe. If there is no gray stripe on the yellow wire(s), it makes no difference which of the yellow wires the gray wire attaches to.

Do not continue on with this thread... start your own.
 
Back
Top