replaced regulator/rectifier...tach worked one trip

drbobp

Seaman Apprentice
Joined
Oct 3, 2004
Messages
46
I have a 96 Johnson 150 Fast Strike. My tach was not working but it did work when tested on another engine. I was advised to replace my regulator/rectifier. I did (CDI) and the tach worked great for one trip. On the next trip, I was heading down the lake and noticed the tach needle jump from 0 to 5000 (I hadn't noticed it on 0...the movement drew my eye). It worked fine for a couple of hours but now it won't work at all.<br /><br />Could this be a problem with the stator? Could it have burned out my new regulator? Any suggestions? Thanks,<br /><br />Bob
 

Laddies

Banned
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Sep 10, 2004
Messages
12,218
Re: replaced regulator/rectifier...tach worked one trip

A loose or dirty connection in the chargeing or at the battery will cause the tach, to fry sometimes or a voltage spike at the rectifier
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: replaced regulator/rectifier...tach worked one trip

In other words you replaced the part, but didn't address what caused the first failure. By far, most such failures are caused by crossed, corroded, or loose battery connections. Battery Switches are another major factor. Not the switch, but somebody switching with the motor running. Big No-no. Back to the dealer for another one. :(
 

drbobp

Seaman Apprentice
Joined
Oct 3, 2004
Messages
46
Re: replaced regulator/rectifier...tach worked one trip

Thanks, I will check the battery connection but the boat has been cranking fine. Could the stator be bad?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: replaced regulator/rectifier...tach worked one trip

The battery connections may be loose but still crank the motor fine. Lose the wingnuts if youre using them. Check the stuff WBW suggested. And yes, one side of the stator can be bad. Is your battery staying charged? Or are you having issues with the battery too?
 

Salty Sal

Petty Officer 2nd Class
Joined
Nov 14, 2003
Messages
143
Re: replaced regulator/rectifier...tach worked one trip

I had a similiar problem. Check the harness that goes to the throttle/control box. Mine (1985 Rude) has pins-<br />male to female. Make sure they are clean and that the connection is snug. And yes- battery problems - <br />connections, etc. can screw up your rectifier.
 

drbobp

Seaman Apprentice
Joined
Oct 3, 2004
Messages
46
Re: replaced regulator/rectifier...tach worked one trip

It seems not to be fully charged when I get back from a fishing trip. The charger shows between 80-90% charge. I assumed this might be the rectifier problem.
 

Joe Reeves

Supreme Mariner
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Feb 24, 2002
Messages
13,262
Re: replaced regulator/rectifier...tach worked one trip

Bob.... The following may be of interest to you.<br /><br />The tachometer sending/receiving setup operates off of the gray wire at the tachometer. That same gray wire exists at the engine wiring harness which is connected to the engine electrical terminal strip. You'll see that there is a gray wire leading from the regulator/rectifier to that terminal strip, and that there is another gray wire attached to it. That other gray wire is the wire leading to the tachometer which is the one you're looking for.<br /><br />Remove that gray wire that leads to the tachometer. Now, find the two (2) yellow wires leading from the stator to that terminal strip. Hopefully one of them is either yellow/gray or is connected to a yellow/gray wire at the terminal strip. If so, connect the gray wire you removed previously to that yellow/gray terminal. Start the engine and check the tachometers operation, and if the tachometer operates as it should, then the regulator/rectifier is faulty and will require replacing. If the tachometer is still faulty, replace the tachometer.<br /><br />If neither of the yellow wires from the stator is yellow/gray, and neither is attached to a yellow/gray wire, then attach that gray tachometer wire to either yellow stator wire, then the other yellow wire, checking the tachometer operation on both connections.<br /><br />I've found this method to be a quick and efficent way of finding out which component is faulty.... the tachometer or the regulator/rectifier. It sounds drawn out but really only takes a very short time to run through. If the water cooled regulator/rectifier proves to be faulty, don't put off replacing it as they have been known to catch on fire with disasterous consequences.
 

drbobp

Seaman Apprentice
Joined
Oct 3, 2004
Messages
46
Re: replaced regulator/rectifier...tach worked one trip

Thank you, Joe!!!! I will do that this afternoon! (First tournament of the bass season for us tomorrow!)<br /><br />Bob
 

jgrisham02633

Petty Officer 2nd Class
Joined
Jan 26, 2005
Messages
126
Re: replaced regulator/rectifier...tach worked one trip

Just got through replacing my regulator only to find out my tach didn't work, turned out to be no voltage at the purple wire. Maybe check to make sure you've got 12 volts on the purple at the regulator with the key on, not running. Good Luck
 

QuarterPound

Cadet
Joined
Oct 3, 2004
Messages
8
Re: replaced regulator/rectifier...tach worked one trip

I am not a mechanic, but when I had the same thing occur, it was due to the alternator going out. Crank the engine and put a meter on the battery and look for 13.6 vts
 
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