If you've only a rectifier and no regulator, what voltmeter behavior to expect?

[pcrussell50]

Just bought a dressed 1983 2.4/200 powerhead. It has no regulator, just a rectifier.

Prior to this, the 2.0/150 I had been running had both the regulator and the rectifier, as separate items, not both together. With this, at different times, I would see up to 15V or down as little as 12 or 13, something like that. Assuming here, that the regulator was responsible for determining which voltage I would see at the volt meter.

So, when I begin using this 2.4/200 powerhead with no regulator, what should I expect to see on the volt meter? 15V, all the time with no drops down to 13V?

I run only a simple lead acid battery and little in the way of electrical draw except a cheap LCD sounder for water temp, depth, volt meter, and speed (via paddle wheel, it doesn't even have GPS).

-Peter

[25two.stroke]

My mariner 175 2.0L 1988 rectifier only:
2 lead acid batteries, washdown, bait pumps, 2 garmins...

13.0v shortly after startup and idling at the dock.
2500 rpms around 13.9v
4000+ rpm the voltage would climb up above 15v

Sometimes it would go up to 16.5v and scare me into shutting down all my electronics. Never hurt my batteries; still it seemed concerning.

Running my Bridgeport with the same setup, no regulator, I never see over 14.9v wide open and typically 12.6v at idle

[pcrussell50]

My mariner 175 2.0L 1988 rectifier only:
2 lead acid batteries, washdown, bait pumps, 2 garmins...

13.0v shortly after startup and idling at the dock.
2500 rpms around 13.9v
4000+ rpm the voltage would climb up above 15v

Sometimes it would go up to 16.5v and scare me into shutting down all my electronics. Never hurt my batteries; still it seemed concerning.

Running my Bridgeport with the same setup, no regulator, I never see over 14.9v wide open and typically 12.6v at idle

If that’s the behavior with rectifier only, I have to wonder if my regulator is doing anything at all, since that’s more or less the behavior I see with a regulator. :shrugs:

-Peter

[25two.stroke]

Regulator is probably doing nothing. Most of the 2 wire ones do nothing. If your voltage goes over 14.5 with the regulator then the regulator is toast.

[pcrussell50]

Regulator is probably doing nothing. Most of the 2 wire ones do nothing. If your voltage goes over 14.5 with the regulator then the regulator is toast.

Damn, I love this place Yep. Old two-wire regulator.

-Peter

[Darkcloud]

Hey guys. I have a 1985 150 merc. Motor wasn’t charging. Changed rectifier and tested at home on ear muffs got 13.6v. I was a happy camper……until the following day when I took her out for a test run. At start up motor was charging at approximately 13.6v. Once I got the revs up about 3500rpm voltage jumped to 17v. In a panic I shut the boat down went through the start up sequence again and motor did exactly same thing. I went back to Mercury dealer (who won’t warrant electrical components) and questioned them on why this was happening and they seem to think it’s rectifier. I have never heard of regulator until now. It’s possible this is the problem
Id like to check this out can you guys help. Where is the regulator
Pete.

[pcrussell50]

Hey guys. I have a 1985 150 merc. Motor wasn’t charging. Changed rectifier and tested at home on ear muffs got 13.6v. I was a happy camper……until the following day when I took her out for a test run. At start up motor was charging at approximately 13.6v. Once I got the revs up about 3500rpm voltage jumped to 17v. In a panic I shut the boat down went through the start up sequence again and motor did exactly same thing. I went back to Mercury dealer (who won’t warrant electrical components) and questioned them on why this was happening and they seem to think it’s rectifier. I have never heard of regulator until now. It’s possible this is the problem
Id like to check this out can you guys help. Where is the regulator
Pete.

Hey mate, it's right on top of the engine, aft of the flywheel. Hopefully this snap helps:


the yellow and red wires are attached to it.

The rectifier is on the side, above the switch boxes.

As you know from my previous posts, it's not unusual for me to see high voltages, I think 16 or so Volts. It also drops down to 13 or so from time to time. I have not figured out any rhyme or reason. Maybe my regulator is actually still working at little bit? If you are using a regular lead-acid battery you are probably fine with 17V. It's lithium bombs that cannot tolerate too high or low charge current or rates. But a lithium battery would be worth more than your (and my) entire motor.

Did you buy just a regulator, or did you buy the $250 (USA prices) rectifier-regulator. They have those, too. It's just that I don't have one and have never tried one.

-Peter

[25two.stroke]

Rectifier will not cause it to overcharge.

Many early 2.0/2.4 engines did not come with a voltage regulator, just a rectifier. There was no voltage regulation. With a 9amp stator and the typical electronics running in a fishing boat there was no need for regulators. Additionally, many owners and dealers removed the regulators when they failed cause they were expensive and pretty much useless.

So...if you don't have a regulator do not be surprised. Your rectifier is not bad, it is performing its job. You can add a voltage regulator if you want to control your charging (if you are worried about boiling batteries or frying fishfinders). Or you can just put more of an electronic load on your vessel and the voltage should come down.

Side note: mercury dealers can warranty electronic parts. All mercury parts have a 1 year warranty against defects. They do no, however, have to accept returns on electronic parts. That being said, its not an issue cause your rectifier is not the problem.

[Darkcloud]

Hey mate, it's right on top of the engine, aft of the flywheel. Hopefully this snap helps:


the yellow and red wires are attached to it.

The rectifier is on the side, above the switch boxes.

As you know from my previous posts, it's not unusual for me to see high voltages, I think 16 or so Volts. It also drops down to 13 or so from time to time. I have not figured out any rhyme or reason. Maybe my regulator is actually still working at little bit? If you are using a regular lead-acid battery you are probably fine with 17V. It's lithium bombs that cannot tolerate too high or low charge current or rates. But a lithium battery would be worth more than your (and my) entire motor.

Did you buy just a regulator, or did you buy the $250 (USA prices) rectifier-regulator. They have those, too. It's just that I don't have one and have never tried one.

-Peter

thanks
lead acid battery may take 17v. I have seen them deform from high voltages. Problem is other electrical components especially sat navs, sounders etc. don’t like the higher voltage.
I just bought the rectifier cause I’m pretty sure that’s all my motor has

pete

[Darkcloud]

Rectifier will not cause it to overcharge.

Many early 2.0/2.4 engines did not come with a voltage regulator, just a rectifier. There was no voltage regulation. With a 9amp stator and the typical electronics running in a fishing boat there was no need for regulators. Additionally, many owners and dealers removed the regulators when they failed cause they were expensive and pretty much useless.

So...if you don't have a regulator do not be surprised. Your rectifier is not bad, it is performing its job. You can add a voltage regulator if you want to control your charging (if you are worried about boiling batteries or frying fishfinders). Or you can just put more of an electronic load on your vessel and the voltage should come down.

Side note: mercury dealers can warranty electronic parts. All mercury parts have a 1 year warranty against defects. They do no, however, have to accept returns on electronic parts. That being said, its not an issue cause your rectifier is not the problem.

thanks for the info.
yes I am concerned about other electrical components and your right my engine doesn’t have a regulator just a rectifier. Are you saying that the voltages I’m seeing is standard on these outboards?

And people just accepted that’s the way it is?
pete

[Darkcloud]

thanks for the info.
yes I am concerned about other electrical components and your right my engine doesn’t have a regulator just a rectifier. Are you saying that the voltages I’m seeing is standard on these outboards?

And people just accepted that’s the way it is?
pete

just to add a question from your first line of the rectifier doesn’t cause overcharging what then is the cause?

pete

[25two.stroke]

thanks for the info.
yes I am concerned about other electrical components and your right my engine doesn’t have a regulator just a rectifier. Are you saying that the voltages I’m seeing is standard on these outboards?

And people just accepted that’s the way it is?
pete

Not really saying its "standard" but its not uncommon. A lot of us don't really care in the fast boats cause there isn't any electronics to fly. AND, we trim a lot more which puts a load on the battery. However, people with fuel injection computers need to watch the voltage cause 17v will fry an ecu. So people do put those 2 wire regulators or the modern 5/6 wire ones.

[Darkcloud]

Thanks for all the info guys. Very much appreciated
if anyone can post instructions or how to upgrade to a regulator or where to buy kit, that would be great

thanks again.

pete

[ChrisCarsonMarine]

These charging systems,9 and 16 v use a full wave bridge rectifier to convert ac to dc to charge the battery via 10 1.5 v stator coils.This makes about 15 volts,and a battery that isn't topped off brings that down a little.Ac power is coming to the rectifier via two legs from the stator(yellow wires).The regulator(start of the art) simply shorts one leg of the stator output when battery voltage reaches 14.5,resulting in a 4.5 or 8 amp charge via the unshorted leg,making the rectifier function as a 1/2 wave bridge.This is why the grey tach feed must not be on the same leg as the regulator,or the tach would not get a pulse when the voltage exceeds 14.5,give or take a bit...Usually the system is fine with a lead acid battery and no regulator,possible exceptions would include a very small battery,long runs,or two motors on one battery,Chris

[pcrussell50]

Should also add that in addition to regulators and rectifiers, there are also regulator-rectifiers combined in one unit. I do not have one of these but I learned about it here and the locals around here seem to have good opinions of them. Is that more or less correct?

I run with a separate rectifier and regulator and see 13-16V depending. Only electronics is single ten year old LCD sounder that doesn’t even have GPS. I use it for depth, temp, speed/distance (old skool paddle wheel) and… voltage. Basically I use my sounder screen as a “digital dash”. Not for fishing.

-Peter