1998 Johnson 90HP (J90TSLECM) voltage too high!!!

[racerone]

I have said it before.----12 volts and wiring are so confusing.----Do not remove that jumper piece !!----Every one of these motors has that and there are no issues at all.----Motor is 24 years old, why would that jumper piece be an issue today ???

 

[brodius]

How bout this rectifier regulator combo from CDI? According to the reviews it has worked for a lot of people on older motors. I am just concerned about it overheating and burning out. Maybe make custom heat sink?

CDI Electronics 193-3408 Johnson/Evinrude Regulated Rectifier - 2/3/4/6 Cyl (1969-2000) https://a.co/d/62Oj6sZ

 

[racerone]

What kind of battery is installed in your boat ?

 

[tg3690]

https://forums.iboats.com/threads/if-you-have-high-charge-voltage-please-read.249235/ This thread has some info about your problem.....I did the conversion and it fixed my high voltage problem......also CDI says to only use regular lead acid batteries, no maintenance free, AGM, or dry cell batteries.

 

[brodius]

I am using walmart ever start lead acid. It says maintenance free but not so sure about that. I can pop the top covers off and check/add water

 

[tg3690]

If you can add water to it then it's not a real maintenance free battery. Should be good.

 

[brodius]

So just to be clear.....the regulator/rectifier in the link above will be installed where the existing Johnson rectifier is? Does it need a heat sink to help last longer? What about the water cooled regulator that I already installed that DID NOT fix?

Also I am getting these voltage readings when running idle in my driveway. Could the already installed OEM reg work under load at higher RPM with electronics running?

 

[tg3690]

If you look up that part # on the CDI website there is an installation PDF....it says to use the existing mounting bolts, so I reckon it mounts in the same spot. Doesn't say anything about adding a heat sink.

 

[brodius]

should i test the installed OEM regulator out on the water even though im getting 16V at idle in driveway? Or install CDI regulator and test that one on the water? Is it bad to have them both wired up???

 

[tg3690]

Is your installed OEM "regulator" the Sierra unit you bought? If so, it is a rectifier only.....no voltage regulation....maybe try the CDI unit and see if it lowers the volts. I would not wire them both up.

 

[brodius]

I did install the sierra rectifier at first but i also installed an OEM regulator (part # 585195) under the flywheel in place of the bracket in the picture. Its a water cooled regulator. This part was never installed so i am assuming this motor/boat was never a regulated system. Once i installed and checked all the wireing im still getting 16V after idling for 10 minutes or so with fully charged batteries. I guess i will unhook the OEM regulator and try the CDI part out on the water soon.

 

[tg3690]

All a rectifier does is convert AC to DC current.....so there is nothing wrong with them.....you want to lower the high voltage.....so try the voltage regulator/rectifier and see if there's a difference. IF you have 16 volts at idle it is probably higher at higher rpms. On my engine it spiked to 18 volts at higher rpms.....that is how the older unregulated systems worked.....not a problem until you add high dollar sensitive electronics on your boat.

 

[440roadrunner]

Just an offhand comment. So far as I know the only way to "regulate" these kinds of charging systems originally, is with what is called a shunt regulator. All they do is create a heavy load across the output to drag down the output.

The "engineers" who designed these should be severely beaten about the head and genitals, and then fired without benefits

In this day and age of pulse based electronics, there "should" be a better way AKA an inverter otherwise known as a switch mode power supply. Build an inverter that operates off the AC output, and outputs a regulated 13.8--14.2V DC

 

[racerone]

Some of the Johnson / Evinrude motors built 60 years ago are running just fine.-----Simplicity works.

 

[tg3690]

"Simplicity" is good....one of the downsides of adding a VR is they can fail without warning....leaving you adrift.

 

[brodius]

"Simplicity" is good....one of the downsides of adding a VR is they can fail without warning....leaving you adrift.

I am on the fence here.... I have some expensive electronics and want to protect my batteries BUT on the other hand im concered about the VR failing on the water like you said. What can be done to make more reliable? Custom heatsink with thermal paste to keep from over heating? I might just keep and rectifier on board in case.

 

[tg3690]

" I might just keep and rectifier on board in case." Good idea....not hard to change out if needed. Added one to mine several years ago....no problems yet. Lots of parts could fail and leave you adrift....so....your motor, your decision. CDI makes good stuff....would follow their directions for installing.

 

[tg3690]

Will be adding a volt meter soon so I can keep a better eye on the charging system while out on the water....

 

[brodius]

I have a voltage gauge on my panel and i verified the accuaracy. Is this what your adding? Im testing the boat this weekend with CDI VR. Ill report back with verdict.

 

[tg3690]

Yes, one of these......good luck with your test. If you have a tach and it starts reading wrong after installing the VR, try switching the two leads that go to the stator....yellow wires on mine.....shouldn't make any difference but sometimes it does.