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tach not working steady alarm goin off

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mike Brehmer

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1995 60hp 3cyl merc. The tach is not working and an alarm is going off. Is this a voltage regulator problem. How can I be sure. How can I turn off the alarm. The alarm is steady. Impeller just replaced and oil injection is fine. how much for a new regulator. Are there any fuses to check.
 
First of all access to a Seloc, Clymer or Merc. factory manual is going to help you. You can get one from this website or another source of your choice such as the local public library. Does the engine run? A continuous alarm is due to overheating or lack of oil. Disconnect the oil tank switch to see if the alarm turns off. If it doesn't then disconnect the temperature switch. If neither switch shuts off the alarm then search for a wiring short in the alarm circuit.

Tachometers are one of the first gauges to malfunction. If the engine doesn't run and/or the battery won't charge the tach. problem could be related to the alternator coil which sends a pulse to the tach. to gauge the RPMs. Check the wires on the back for corrosion. There should be a few switches on the back of it. Spray a little WD-40 into each switch, remember their original settings and move the switches back and forth several times. Before replacing it make sure the alternator wiring is not corroded. If it still does not work buy a new one. You may be able to get it here. If not, send me a PM; I have a reasonably priced source for NOS gauges.

Is there a voltmeter in the dash? It would indicate whether the regulator is functioning. It is a cheap charging/battery trouble indicator and easily installed. Just connect to a ground wire and 12 volt purple wire under the dash.
 
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The motor works great and runs fine. Its just the steady alarm while I'm am boating. Just bought the boat which was in storage for the last five years. It as well taken care of by original owner. Volyage gauge on boat indicates just under 12v. motor was was completely checked out and carbs cleaned starts and runs great. no rust anywhere in the motor but not ruling out short.

I have a full service Merc manual

Mechanic advised that overheat alarm is intermittent. He wanted to change the stator which they don't make anymore. Currently my faith in this mechanic is questionable and have spent 1,200.00. He wanted to changed water pump. I found that the gasket was broken. Installed new gasket $5 and installed new impeller $45 and the pump works great. Oil injection also working fine.

electrical is not my strong point but a want to learn how to fix this motor on my own. Now that season is over will try and learn thie electrical on my own. Also retired. Give me a mitre saw or hammer but wires and shorts ??????
 
Volyage gauge on boat indicates just under 12v.
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Engine off. Measure the voltage at the battery w/a full charge. The battery should read between 12.30 and 12.80 volts. Measure the voltage at the battery gauge. It should be the same voltage or - 0.02 volts. The voltage will be towards the higher value on a newer battery. If the voltage drops by 0.05 volts suspect corroded wiring or connectors.

Engine on w/the RPMs at 1500 for 5 minutes. Measure the voltage at the battery it should read between 13.00 and 14.80 volts; the closer to 14.80 is better. Measure the voltage at the battery gauge. It should be the same voltage or - 0.02 volts. If the voltage is 15.0 volts or higher then the regulator is not working. If the voltage is less than 13.00 volts w/a good battery then suspect the rectifier module or stator or both are defective. Use the manual to ohm test the rectifier and stator per the specs. listed.
 
Just bought the boat which was in storage for the last five years.
Click to expand...
Check for knawed wiring from mice or corroded wiring especially under the flywheel if the voltage readings are wrong.
 
First off find new mechanic.
The steady alarm is probably coming from the lo-oil sensor in the tank. That was a common problem. Find the two blue leads at the bottom of that tank and unplug them. If that does not work than unplug the tan/blue lead from the temp sensor on the front of the motor. The circuits are wired so that the horn rings when the tan/blue lead connects to ground. There may be a short to ground on that wire.

As for the charging system, the battery voltage should be 13+ at 2000 RPM. The system works by sending AC power from the stator (yellow leads) into the regulator or rectifier to change to DC power to charge the battery. THe best way to test the system is with a DVOM set on AC and slip the meter prods into the yellow bullet plugs and start the engine and if the meter reads 24 volts than the regulator/rectifier is bad. (open circuit) IF it reads 0 than unplug the leads and check the stator again. If the power comes back on that the regulator is bad. (short circuit) If there is still no power than the stator is bad.
 
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Folks tks for the info. Ran the engine just before winterising it. battery was at 12.5 v before running the motor. Then ran it for about 5 minutes at above idle speed (remember no tach) and the 12.5v remained the same.
The manual states I can check the stator w/o removing it and this will be done in spring. Any suggestions on where to get these parts if needed, as they don't make Stator for that model anymore. Sator 300$ rectfier $200 is this about right???
P.S. new mechanic would be hours away.
 
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