Johnson 90hp TACHOMETER QUESTION

Joined
May 2, 2007
Messages
6
I've got a 2003 Johnson 90hp & my tach wont budge. I just bought a 2003 angler center console. Everything else seems great on the boat but its real difficult to get to my wiring...even If I did, I wouldnt know what to do. How do I find out if the problem lies with the tach itself...the wiring to the tach or the wiring on the engine end of things? I've aways had older boats / motors...so there is alot more wiring than im used to lol. My first guess is its prob. just oxidation or a crappy connection. I cant imagine the tach failing on a 2003...not yet anyway. Any tips I could try that wont require a degree in rocket science or special tools?

Thanx everyone
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,536
Re: Johnson 90hp TACHOMETER QUESTION

Fish, The tach runs off of the stator, which also charges the battery. Does your battery charge? If you have a voltmeter installed in the dash you should see 13V or more when the motor is running. If no voltmeter, you can check the voltage at the starter solenoid battery terminal on the motor, when the motor is running.

The voltage requlator is located on the top rear center of the block, above the spark plugs, under a plastic cover with 4 screws. My '98 V-6 has a yellow wire, a yellow w/grey wire (both are stator output AC Voltage), a purple wire(+12V when ignition switch is on, a grey wire (tachometer signal) and a red wire (battery charging). If your regulator has the same wires, you need to check for continuity between the grey wire at the regulator and the grey wire on the tach. If it is good, check for continuity to ground. There shouldn't be any.

You might like to get a manual for the motor. It will have a tach circuit troubleshooting procedure.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson 90hp TACHOMETER QUESTION

i agree with dirty connections, or the wire got pull off, the tach. also wiggle the plug going into the remote control. check and see it the battery is being charged, if it is not the rectifier, might be bad, it is what converts the AC produced by the stator, to DC current to charge the battery and run equipment. it is also the sender to the tach.

typing at the same time. basicly we said the same thing.
 
Joined
May 2, 2007
Messages
6
Re: Johnson 90hp TACHOMETER QUESTION

Thanx guys!
The stator / charing system is actually working great. Im going to look into that grey wire. I bet it is something silly like a loose conection like a ground or something.
 
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