force 125 overcharge problem

[Siskiyouline]

I have 125 hp force engine. I've owned this motor for 10 years now and have never had problems such as this. As soon as the rpm's come-up to 1000 rpm (which is where the alternator cut-in) the voltage climbs to 18 volts. I have verified that this is correct and it has never charged above 14.5 volts in the past. I have checked the rectifier and it checks okay. This motor has no regulator according to the manual and also verified by inspection. Anyone know how this system regulates the voltage so that I don't explode my battery and/or ruin my electronics?? <br /><br />Battery is one year old and is not sulphated, it also load tests okay.<br /><br />Thanks!!<br />Bud

 

[eurolarva]

Re: force 125 overcharge problem

Hi Siskiyouline. When you are measuring your voltage are you sure your meter is set to the DC volt range instead of the AC volt range. A rectifier converts ac to dc and will still have an ac ripple on the dc side. It is impossible for a rectifier to eliminate all of the ac volts so when measuring on ac you will have a higher volt reading.<br /><br />My chrysler manual shows a lot of the 125 hp motors having voltage regulators built into the rectifier. It also shows some models with stand alone voltage regulators. <br /><br />Hope this helps. Good luck

 

[12Footer]

Re: force 125 overcharge problem

The regulator (be it as it may) is integral to the rectifier. If you get no AC spike off of the DC leads (to battery) the rectifier is fine, but chances are your battery has cooked. Test with a known good battery hooked-up. This is very common on many outboards built before 1992. Some will boil a battery to death in no time. I have learned form others here, different ways of approaching this problem. One novel idea that works quite well, is retrofitting an aftermarket or auto regulatoron the output of the rectifier.<br />Another solution is to run a dual bettery setup, and run all eclectrics and elctronics off the offline battery, and switch then often. This is because the batteries will not melt down even with 24VDC input,as long as they can accept the charge. It's when they approach full charge that the electrolyte starts to boil.<br /><br />The integral regulator is woefully inadequate on Mercs so-equipped also.