1988 Mercury Charging

[Schnidly]

I own a 1988 Mercury 90hp OB302485 outboard. I replaced the rectifier a couple years ago, can someone tell me if I should have a voltage regulator on my motor? I have found none, does the rectifier act as the regulator?

 

[Laddies]

Re: 1988 Mercury Charging

No the rectifier is not a regulator, but if you are experinceing a over charging problem you could replace the rectifier with a regulator

 

[Schnidly]

Re: 1988 Mercury Charging

Thanks Laddies, may sound naiave on my part but I was taught the only stupid question is the one not asked. Anyways, what does the rectifier do if it does not regulate voltage? I know a rectifier converts ac voltage to dc voltage, isn't this what keep the battery on the boat charged? I see at times my volt meter in the dash go up some when the motor is running and then back down and I am assuming this is when the battery is charging? Also, my motor diagram shows no voltage regulator, or if there is I cant find it.

 

[Laddies]

Re: 1988 Mercury Charging

Your right all a rectifier does is convert AC to DC and a regulator maintains a max. voltage by bleeding some off to grd., that why differant people will say thier regulator has burned places in it. You said you had a rectifier so I haven't checked but some 90HP have regulator yours could be one, rectifiers have 3 wire studs and regulators have 5 wires which is yours?

 

[Schnidly]

Re: 1988 Mercury Charging

Hi Laddies, mine is a 3 wire post system. Any more information on how this rectifier maintains battery voltage would help.

Thanks

 

[Laddies]

Re: 1988 Mercury Charging

It's the simplest system, the stator winding produce a rather low amperage AC current that the rectifier converts to a low DC amperage that charges the battery and hopefully the unit will use enough power so the battery does,'t over charge. When engines used battery current for the ign, system it was seldom a problem but with todays ADI ign the battery is only used to restart the engine, if it is a unit with a lot of electrical accs. to use electricity thenthe system won't over charge the battery

 

[Schnidly]

Re: 1988 Mercury Charging

Hi Laddies, my starting battery is used for starting the engine and the power trim and tilt. I have a deep cycle battery that operates all the accessories, trolling motor, bilge pump, livewell pump etc...... Any more information on the working of the rectifier on my engine would be much appreciated!