Electrical Help 1985 Johnson 120

[Playin Thru]

After trying to "simplify" some electrical things...the motor's wires were connected to the wrong terminals on the battery (pos. to neg.). The motor gave off a considerable amount of smoke and I noticed what appeared to be a ground wire at the top of the shaft was fried. Was this wire here for that reason? How do I go about replacing it? The motor still runs fine, I just don't want to cause any more harm or get stranded. Thanks in advance for you help.<br /><br />PT

 

[Dhadley]

Re: Electrical Help 1985 Johnson 120

Welcome PT!!<br /><br />Most likely the water cooled regulator/rectifier took a bad hit. Since the motor still runs did you notice if the tach works?<br /><br />Describe more about the ground wire. Its near the top of the crankshaft or driveshaft?

 

[Joe Reeves]

Re: Electrical Help 1985 Johnson 120

It's impossible to know what wire you're speaking of unless we were actually there. However, it sounds like the "Voltage Regulator/Rectifier" which is located on top of the powerhead and to the rear of the flywheel has shorted out due to reverse polarity.<br /><br />Continuing to run the engine will only result in more problems.

 

[Playin Thru]

Re: Electrical Help 1985 Johnson 120

wire is connected with what looks like a ground screw at the top of the lower unit that's visable without removing the hood. I can't tell where it runs from there because it's gone. As far as the tach question goes that was something we were trying to fix when this happened so i can't confirm if it's working. <br />Like i stated before the motor runs great, same as it did prior, if it is the "Rectifier" why does it still run good.

 

[Silvertip]

Re: Electrical Help 1985 Johnson 120

The engine runs fine because the regulator/rectifier has nothing to do with the ignition system. This device is part of the battery charging system. It is also the source of the pulses that provide the reference for your tachometer. Thats why people are asking if your tach works. If it does, the regulator may still be ok (but don't hold your breath).

 

[Playin Thru]

Re: Electrical Help 1985 Johnson 120

I'm very green with this stuff so bare with me. If the "regulator/rectifier is shot then what is it's function and what are my conserens if i con tinue to run it this way.<br /><br />Thanks for your patience,<br />PT

 

[Playin Thru]

Re: Electrical Help 1985 Johnson 120

One more question, if this rectifier is shorted out, is it a major repair to fix it? Maybe something i can do myself?

 

[Dhadley]

Re: Electrical Help 1985 Johnson 120

You can do it yourself if you have the equipment to pull the flywheel.<br /><br />The rectifier part has to do with charging the battery and the regulator keeps it from overcharging. Theres more to it but thats the basics.<br /><br />If left un-repaired its possible for the wiring to catch on fire. And the motor wont charge the battery.

 

[Silvertip]

Re: Electrical Help 1985 Johnson 120

There are two parts to a charging system. The engine outputs AC (alternating current) which must be converted to DC (direct current). The rectifier does that. As mentioned in other posts, the regulator controls the charging voltage and keeps it in a range that prevents overcharging the battery(ies). If you aren't sure what happened to the wiring and are not comfortable working with these systems, perhaps you should leave it to your favorite service facility. Just be sure you explain fully what you did.

 

[Playin Thru]

Re: Electrical Help 1985 Johnson 120

Thanks Guys! I have an appointment to get it fixed this week.