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Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 14299
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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Jeff I have a question about the testing protochol rectifier

Customer Question

Jeff I have a question about the testing protochol for a rectifier on a 100F four stroke.
Submitted: 1 year ago.
Category: Boat
Customer: replied 1 year ago.
Also the motor model number is ***** TXR2
Expert:  Jason replied 1 year ago.
Hello my name is***** isn't online right now. Would you prefer to wait for him or do you require more immediate help?
Customer: replied 1 year ago.
Immediate would be better.
Customer: replied 1 year ago.
I read a test rectifier test script that Jeff had written for a F115 yamaha and I used it on my F100 (similar motor). However my results were different. I want to validate my test
Expert:  Jason replied 1 year ago.
I'm not able to read what you are reading. What kind of problem are you having, and what did you to do test it?
Customer: replied 1 year ago.
I have the exact same problem with my boat motor not charging that another customer had. Here is Jeff's response..I will be happy to assist you. If you have a question or need clarification please post back at any time.
A fully charged battery at rest measures about 12.5 volts. You should be charging 13.5+. So by showing you are at 9.5 to 12.7 you are not charging.
You have a rectifier/regulator system. In almost all cases that is the problem. There are only two parts to your charging system the stator which is a series of coils under the flywheel and the rectifier/regulator.
Disconnect the battery.To test the stator you will need an ohm meter. Set it to the 1 scale.
Disconnect the stator harness from the rectifier in the front of the engine.
Test from each of the green wires from the stator. Mark each green wire #1,2,3.
Test from #1 to #2 then from #1 to #3 then from #2 to #3 the reading should be .2 to .8 ohms. If not the stator is bad.
If the stator checks bad then the rectifier is probably OK but to check it check the green wires on the rectifier side of the harness; Put your meter to the 10 scale, put the red lead on the red wire of the rectifier then the black meter lead to each of the green wires one at a time, you should read 100-300 ohms. Now put the meter's black lead to the red wire and the red meter to each of the green wires and you should not get a reading.These resistance tests should tell you if the problem is the stator or the rectifier/regulator.Read more: http://www.justanswer.com/boat/3x847-yamaha-115txrc-four-stroke-outboard-not-charging.html#ixzz3eCPQc6Vj
Customer: replied 1 year ago.
The stator test worked exactly as Jeff explained it would . I ran into a problem when testing the rectifier.
Expert:  Jason replied 1 year ago.
Got it. How did you test the rectifier?
Expert:  Jason replied 1 year ago.
Does your meter have an AC millivolt scale?
Customer: replied 1 year ago.
Exactly as Jeff's direction. The problem was the results were opposite of what Jeff stated. The read lead tester to red wire black lead to green wires tested no ohms. The black lead to the red wire with the red lead to the green wires tested ohms of 323 to 353... That result is opposite of his post. Is the test protochol accurate or due I have a bad rectifier?
Expert:  Jason replied 1 year ago.
Does your meter have an AC millivolt scale? Is your meter analog or digital?
Customer: replied 1 year ago.
Fluke digital..It does have a setting MA AC... Is that what we are looking for?
Customer: replied 1 year ago.
Nevermind that is amp test. Yes it has MV DC setting
Expert:  Jason replied 1 year ago.
What model is the meter, i'll look it up.
Customer: replied 1 year ago.
See my last post it is a 77IV (I got it now)
Expert:  Jason replied 1 year ago.
Got it. What condition is everything in right now. Is the regulator installed on the engine, or is it on a workbench?
Customer: replied 1 year ago.
Everything is installed, the wiring connector to green leads are unplugged though
Expert:  Jason replied 1 year ago.
Hook the regulator back up and connect the green leads. Hook up some water. Stick the meter on the battery. Start and run the engine and run it up to 2000 rpms. 1. Set the meter to DC Volts - What does it read?2. Set the meter to AC volts. set the range to 6.000 V - What does it read?
Customer: replied 1 year ago.
Ok... I will get back to you.
Expert:  Jason replied 1 year ago.
okay let me know what happens .
Customer: replied 1 year ago.
Pre-startup DC voltage 11.92after startup running around 2200 RPMDC 11.84AC at 6.00 scale .012
Expert:  Jason replied 1 year ago.
Have you checked the 30 amp fuse on the engine?
Customer: replied 1 year ago.
No...I'll check
Expert:  Jason replied 1 year ago.
Okay let me know.
Customer: replied 1 year ago.
30 amp fuse continuity checked good.. Also I checked the auxiliary 20 amp fuse. Also good.
Expert:  Jason replied 1 year ago.
Do you show voltage to the fuse? At the end of it?
Customer: replied 1 year ago.
Ok with motor running at idle.. Phase to ground voltage test was 11.76... (I tested both sides of fuse individually)
Expert:  Jason replied 1 year ago.
Without the engine running, if you touch the end of the fuse with your meter do you show voltage at the end of it?
Customer: replied 1 year ago.
Engine not running repeated same test....voltage 11.80 on both sides of fuse.
Expert:  Jason replied 1 year ago.
Do you have another battery you can use, your battery is dead, and the charging system isn't going to charge properly with a dead battery.
Customer: replied 1 year ago.
Ok... let me see what I can do.
Expert:  Jason replied 1 year ago.
Okay let me know what happens. A charged battery should be reading 12.6. 11.8 is a dead battery. The regulator did measure correctly. So lets see what happens when you get a new battery in it.
Customer: replied 1 year ago.
Ok... another battery... 12.52.. Engine running with it 12.44
Expert:  Jason replied 1 year ago.
Got it. Now coming out of the stator, the wires that plug into the regulator. Are they 3 white wires, or 3 green wires?
Customer: replied 1 year ago.
wire plug to regulator 3 green wires.
Expert:  Jason replied 1 year ago.
Disconnect the stator. On the wires that run to the stator, measure the resistance between each of the green wires. For example, just label them 1,2 and 3in your head. Measure between 1 and 2, 2 and 3, and 3 and 1. Let me know what you get for readings.
Customer: replied 1 year ago.
from the harness to the stator (Those are white wires) all tests registered (.4) ....... FYI as stated in earlier post (green wires to regulator)
Expert:  Jason replied 1 year ago.
Got it..... Well... We've done all of the tests that we can do with the meter that you have. In order to continue an adaptor tool called a DVA is required for further testing. Click this link, this is what a DVA is - https://store.snapon.com/Multimeter-Accessories-Adaptor-Direct-Voltage-P649400.aspx Did you want to get your hands on one and get back to me?
Customer: replied 1 year ago.
Any chance one of those adapters are sold at a retail outlet.? Ordering will take a couple days. Can you send me the test sequence so if I do get one over the weekend I can run the test?
Expert:  Jason replied 1 year ago.
No, it's definitly something you would have to order. The Snap on one is 35 bucks and actually a deal, as others are way more expensive. The deal is the voltmeter will not read outboard voltages. Meters are designed to read RMS/Average voltages. Outboard work on PEAK voltages. What you want to do is hook the stator back up to the voltage regulator. Run the engine at 1500 rpms. Back probe the electrical connector and check voltages on those white/green wires. You should show 15.5V. If it's low the stator is bad. If it's good, the regulator is bad. Does that make sense?
Customer: replied 1 year ago.
Should the black lead of the tester be connected to a ground while I am testing the back of the connector?
Expert:  Jason replied 1 year ago.
No, what you would do is set the meter to DC volts and then measure between each wire again. 1 to 2, 2 to 3, 3 to 1. Each set of wires needs to read roughly 15.5V
Customer: replied 1 year ago.
Got it, motor running 1500 RPMS. test back of connectors between wires. How far below 15.5 would you consider bad stator?
Expert:  Jason replied 1 year ago.
Probably no lower than 15... The specs on Yamaha engines are pretty tight.
Customer: replied 1 year ago.
Just to be clear. The stator must be connected to the regulator with the motor running to perform the test. correct?... The back sides of the connector are sealed. If thats the case I will need to stab the wires with probe to read the voltage.
Expert:  Jason replied 1 year ago.
Correct. You want to test the voltage with the circuit "loaded". If you don't have any back probes to get in the electrical connector, hen use a map pin and push it through the wire in order to get a reading off of that

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