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Not Charging and Tach Not Working

Z

zee_man

New member
"Johnson 1990 175HP STLES

I

"Johnson 1990 175HP STLES

I am having problems with both my charging system and tachometer. After researching similar problems I ran the Joe Reeves water cooled rectifier test. After verifying the continuity of the gray wire on the back of the tach and the grey wire at the terminal strip, I took the gray wire off the terminal and connected it to the yellow/gray wire on the terminal. When I did this I fully expected the tach to work and point to the rectifier. It still didn't work. Next I took my multi-meter to test the voltage of the battery - 12.67 - started the engine and voltage remain basically the same. I expected it to go up to around 14+ volts. The voltage meter on the boat also reads around 12 volts.

I guess it's possible that both are faulty. Are there other tests or steps that I should be looking at."
 
"Mike.... make sure that you h

"Mike.... make sure that you have 12 volts being applied to the proper terminal of that tachometer and that the ground of the tachometer is indeed gounded. Key on should result in having the tach drop from its shut off reading to absolute zero.

If the power source and ground are as they should be and the tach doesn't drop to zero, I would assume that something is wrong with the tach.

If all is well (above), make sure that the "gray" wire leading from the engine wiring harness (not from the reg/rec assy) has continuity all the way up to the tachometer.

If still okay, connect that a "gray wire to the other stator yellow lead. Let us know what you find."
 
"Joe, how many times have you

"Joe, how many times have you in 30+ yrs witnessed 2 seperate problems arise at the same time and been fooled they are the result of one component failure."
 
"Mike

I have an 89 200XP th

"Mike

I have an 89 200XP that reacted to the rectifier test the same way yours did. I replaced the Tach thinking that if I ran the test properly, as I did, then the Tach must be at fault. This turned out to be Not True. Upon closer inspection of my stator, I found that I had the infamous melting black goo seeping around the stator coils. I then replaced the stator & rectifier, which completely solved my charging & Tach problem.

It's my belief that a failing stator can cause the failure of the rectifier.

Mark"
 
"Test the continuity of the gr

"Test the continuity of the gray wire and that was fine.

Have 12 volts at the tach, cleaned all wires and posts

Tach does return to absolute zero.

When I connect the gray wire to the yellow- gray wire - still nothing.

Just as an aside, tested charging system at the battery and 12.57 volts. Pretty much the same with motor on or off.

I will check the stator, as Mark suggested, but don't have the right fly wheel pull. Have the one with three arms, center bolt.

The good news is the motor is running nicely on the muffs.

Thanks again for your replies, any other tests or suggestions are welcomed."
 
"u can test for a/c current fr

"u can test for a/c current from stator,..but,here is a quick test-- umust have continuity,between the yellows,and they must not be grounded..look at the stator well,any signs of overheating,repl it AND volt reg/rect...no signs of overheating,the usual prob is the reg/rect.a prob w/tach AND charging is nearly always the reg/rect.,but,..stator tests are a neccssity as well."
 
Take a flash light and check c

Take a flash light and check carefully under your flywheel any sign of melting brown stuff replace the stator and save your self some money
 
"There is continuity between t

"There is continuity between the stator leads. After thoroughly checking the stator there is no brown gooey stuff around the wiring. Looking from the back of the motor there are two large "transformers or capacitors" at 12 and 6 o'clock. They have a brown epoxy on them, but it hard and dry. The wiring is very clean.

Reg/Rectifier?

Thanks again."
 
"Mike , simply use a digital m

"Mike , simply use a digital multi meter with the engine running you will have 13 plus volts DC at the battery leads if not its the Regulator."
 
"Thanks, that's what I tho

"Thanks, that's what I thought from the beginning. I wanted to make sure I ran through all the tests before I put any money into it. From my description of the stator, that looked good?

I appreciate everyone's help."
 
"No, my bet is that the stator

"No, my bet is that the stator is bad.
From all that you have said...plus this statement....

"When I connect the gray wire to the yellow- gray wire - still nothing."

That statement tells me there is no stator output.

I would check the stator output, the AC voltage across the two yellow wires when running, before shotgunning a reg/rect. Only problem is I don't know what the output voltage should be at idle speed. I have looked at my service manual and it is not in there. Maybe someone can add that info.
Also, if you are gonna shotgun the problem, the stator is easier to replace!

Please be sure to post back with the resolution."
 
"Thanks Doug, if anyone has th

"Thanks Doug, if anyone has the stator output at idle for 1990 Johnson 175 HP I would appreciate it. I really not sure what the problem is. From everything I read, it looked like the Regulator/Rectifier. Now I am learning that the stator can cause similar issues. Neither one looks difficult to replace. I am learning along the way. I am only getting 12.5 volts at the battery cables. I'll check what my stator output is at idle tomorrow. I put my meter on the yellow and yellow gray wires and see what comes out. This one of three problems I need to resolve. Those posts for a later date.

Thanks again."
 
"Just a bit of advice....
Rem

"Just a bit of advice....
Remember that this is AC not DC, so set the meter accordingly. We also do not know the frequency...so your AC voltmeter may not measure right, but it will measure SOMETHING. And, I would measure it disconnected from the reg/rect. I don't see how it can harm the stator to run disconnected since there will be no current flow.
What really harms the stators is an excessive current flow due to a bad battery, a bad reg/rect, or a stator winding short...anything that will increase the current flow is bad for the stator. Will cause the melting...which you do not have....
But I am really wondering if you get anything at all on the meter.
Do you have the terminal strip connections? If so, it will be an easier measurement.
I know...the two parts are very expensive...so that is why I highly recommend as much testing as possible before replacing anything.

This is going to be a very interesting experiment."
 
I do have the terminal connect

I do have the terminal connections. Do I need to remove the two yellow wires from the terminal to test? Or should I do both and see what the readings are both ways?

The meter I have can read above 200 volts. Didn't know their were different frequencies for AC voltage.

Thanks.
 
"If you can, measure it both c

"If you can, measure it both connected and disconnected.
Disconnected, it may show a much higher voltage than when connected. When disconnected, there will be no current flow in the stator coil, and therefore no "back EMF" to "force" the voltage down to normal running levels.
But, when connected, if there is a short internal to the reg/rect, the voltage you read may be zero, due to the reg/rect fault.

I am just really interested in what readings you get...this whole experiment is sort of a crap shoot anyway.

I sort of believe that you will measure somewhere around 20-25 volts AC when you do the test, IF THE STATOR IS GOOD. It all depends on how the circuit is designed inside that reg/rect.

And you don't need to worry about frequency, etc. I was just sorta thinking out loud there....

Does anyone reading this know the frequency of the voltage generated by this stator as designed?
I am wondering if it is 6o hz, because the settings for tach switches is 6P, and 360/6=60..."
 
"Mike Z,
Are you reading this

"Mike Z,
Are you reading this post?

Rectifier / Regulator going bad??

It is talking on the same subject."
 
"Here are the results, did n

"Here are the results, did not matter connected to the terminal or not connected, it jumped from 29 to 30 AC volts from the stator wires.

Not sure if that is good or bad, assuming it's good.

Doug, not sure what post your were asking me to read.


Thanks again for the help."
 
"Doug, found it, should this

"Doug, found it, should this be the next test:

If You have a multimeter with AC reading would do, with Hz reading even better.
Hook the + to the gray wire, - to any black/ground. Run the engine and check if You loose signal. If signal gets lost, Your regulator is defective.

Thanks."
 
"This is good news, great news

"This is good news, great news.
You got 30 v AC across the stator at idle...
The stator is putting out....

Then I would replace the reg/rect.

"Rectifier / Regulator going bad??" is the title of another post on this same subject...read it, interesting....

When I get a chance, I am going to do the same measurement on my engine, and compare. Thanks for taking the time do do this test.

Please be sure to post back with the final results."
 
"I ran the test with the gray

"I ran the test with the gray wire to the positive lead from the multi meter. My signal stays constant at 19.6 V. This confused the situation.

The stator is putting 30 AC volts out at idle, the battery leads are showing 12.6 DC volts at the terminals. The tach is not working yet the gray wire is putting out a constant signal.

All seems conflicting data."
 
"Yes it does conflict...I gues

"Yes it does conflict...I guess. We really have no reference books to know what we should be seeing on a good system.
I wish I could get to my motor to do the same tests...but I can't right now.
I do know this...on my engine, at idle with the battery charging and everything working as it should, the voltage when charging is 14.7v.
That is for sure.

Your batt voltage is 12.6. It should be 14.7 when charging. So it is not charging.

Also, 19.6v on the gray wire from the reg/rect.? Was that AC or DC? Only an AC signal will drive the tach....

You have stator output (30v)....
I still think it is time to repl the Reg/rect."
 
"Here is one in the win column

"Here is one in the win column. The end result was a bad regulator/rectifier. After pulling out the old one and testing it, nothing was flowing in either direction. The new CDI rectifier has current flowing yellow to red. My tach started to work as well which surprise me. I thought both were bad. No matter where I connected the gray wire, the tach never responded.

Getting the flywheel off took some effort. Thanks to everyone for your help. Doug thanks for the call and advice, it was as you expected."
 
"I have a 25 Johnson - Seahors

"I have a 25 Johnson - Seahorse

I have a red and a black wirning harness out of the front of the motor

I am assuming that is the charging system

When I put my volt meter on it, at idle its at 9 volts then at higher rpm it goes to like 24 v

Is that ok?

Or is there something broken?

Do I just plug a battery to the otehr end?"
 
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