checking voltage output / charging

[OldSkool67]

can anyone provide me the procedure for checking the voltage output from the stator... both my batteries went dead and they are newer... i suspect an issure with the charging system.

[seabob4]

Ryan,
First check the "rest" voltage on the batts, that is with no load applied on them at all.  Good batts fully charged should show somewhere around 12.35 to 12.6V.  Start the engine, now check the voltage on the batts.  They should show around 13.65, even up to 14V.  Don't wanna go much higher.  If this is what you see, then the charging system is doing it's job.

If the voltage stays the same as the "rest" voltage, then obviously you have a charging issue.  And, if the voltage is around just over 13V with the engine running, this would indicate a dead cell in the batt...

[OldSkool67]

We have no voltage increase when the engine is running.

Ive checked the leads from the stator for ac voltage and did not get much more than 30 volts, from my understanding I should have 150+.

Anyone give me the test procedure for the voltage rectifier?

Im sure its in the manual, Im going to try to find one this weekend when Im out and about.

[seabob4]

Ryan,
Just did a little reading...http://www.marineengine.com/boat-forum/ ... tor-582905

Yeah, I know it's not a 235, but it is a V6 Evinrude.  Sounds like the diode is history, which would explain the discharging of the batts.  See what the manual says as far as testing, but it doesn't look good for the rectifier...

[OldSkool67]

My tach is dead too... that has never worked in the 3 months I have had the boat.

Gonna have to find the manual and figure this mess out.

[John Jones]

I had the same issues with my 235 Oceanrunner.  No charge, dead tach.  Voltage Regulator/rectifier whatever they call it fixed it all.

[slvrlng]

Before just replacing the rectifier you need to test the stator. Remove the rectifier cover, Separate the stator yellow and yellow gray connector. Connect a ohmmeter lead to each lead. It should show 0.12 +- .07 ohm. If it doesn't replace the stator. Then check for a grounded condition. Connect one lead to a clean ground on the block then to each lead, either lead should show a high reading, if it doesn't check the wiring because the stator or its leads are grounded.

To check the rectifier, you really need a carbon pile load tester. You also need to run the motor at 4500 rpms which can be a issue unless you have a tank or a engine dynomometer. First to check the rectifier is getting power disconnect the purple lead connector. Check the voltage at the lead with the key switch in the ON position. If its not showing full battery voltage there is a wiring problem in between the switch and the rectifier.

[OldSkool67]

Before just replacing the rectifier you need to test the stator. Remove the rectifier cover, Separate the stator yellow and yellow gray connector. Connect a ohmmeter lead to each lead. It should show 0.12 +- .07 ohm. If it doesn't replace the stator. Then check for a grounded condition. Connect one lead to a clean ground on the block then to each lead, either lead should show a high reading, if it doesn't check the wiring because the stator or its leads are grounded.

To check the rectifier, you really need a carbon pile load tester. You also need to run the motor at 4500 rpms which can be a issue unless you have a tank or a engine dynomometer. First to check the rectifier is getting power disconnect the purple lead connector. Check the voltage at the lead with the key switch in the ON position. If its not showing full battery voltage there is a wiring problem in between the switch and the rectifier.

I checked that yesterday and got .950 / my seloc said it should be .12 to .22
From what i can see and checking my model number I have a 35 amp system, which means everything is twice as expensive.
The stator was supposedly replaced within the last year. When I bought the boat he gave me a box with old parts in it which included an old stator. So not real sure which way to go with it now other then changing some parts.

any thoughts?

[slvrlng]

What model # is the motor?

[OldSkool67]

E235TLCO

[slvrlng]

http://www.marineengine.com/newparts/pa ... ne=&Model=

http://www.marineengine.com/newparts/pa ... ne=&Model=

These are some really good people to deal with!

[GoneFission]

The tach gets the RPM reading from the stator through the rectifier.  So the tach won't work if either is bad.  The rectifier is much easier and cheaper to replace, so I would start with that.  You usually need to remove the leads to get accurate readings on the stator (see the specs above).  You should also have a voltage regulator (or combo rectifier) if you have the 35 amp stator setup.

[slvrlng]

The tach gets the RPM reading from the stator through the rectifier.  So the tach won't work if either is bad.  The rectifier is much easier and cheaper to replace, so I would start with that.  You usually need to remove the leads to get accurate readings on the stator (see the specs above).  You should also have a voltage regulator (or combo rectifier) if you have the 35 amp stator setup.

I f you only replaced the rectifier, couldn't a bad stator burn the new rectifier up or would the voltage regulator protect it?

[GoneFission]

[quote="slvrlngI f you only replaced the rectifier, couldn't a bad stator burn the new rectifier up or would the voltage regulator protect it?[/quote]

A bad stator does not produce output, so it will not burn up a rectifier.  Some marine voltage regulators are the opposite of automotive types - the auto regulators open the circuit above around 13.8V - the marine ones close to ground around 14V.  Weird!  And the marine versions cost 10 times what the automotive versions cost - a Mercury voltage regulator is over $200!!  I'm working on a changeover for stator- based outboards that uses a cheap (less than $20) auto-type voltage regulator with a cheap (less than $10) 50A bridge rectifier that would replace both units in most outboards with a more reliable and much less expensive option.  Hang in there until we have the final version skunk-worked out...