We have a sporadic light that keeps coming on when we motor sometimes the cooling light and sometimes the charge light. In both cases the buzzer goes off as well. I checked the alternator and it was charging when the charge light was on and I pulled apart and checked the cooling system from head to tail and all was working (even pulled the pump apart). We cant see any wires crossed or short circuiting behind the starter panel. This started last summer and occurs about every other trip - the light will stay on until we come to harbour and the buzzer to - unless we turn off the key and keep motoring (not a good idea) any ideas?
Yanmar in Yamaha 30 - charge light comes on
- Thread starter Nick H
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I'm not sure what the problem may be. But why is it a bad idea to turn off the key and keep motoring? I'm afraid of the answer, since that's what I always do.
Ralph
Had a similar problem. It turned out that the sensor wire connector came loose from the sensor. I had to replace the unit. (2GM)
Hi Nick,
My boat’s home is just around the corner at T-Bird Marina. I think your Yamaha 30 is similar to a Yamaha 25 where the motor is mounted under the V-berth and you probably have an YSM-12.
Based on your description, I suspect there is an intermittent wiring problem in the alarm circuit. Check the wiring harness and sensor connections. The alarm circuits are described in my YSM-12 manual in Chapter 11 (electrical) Section 5, starting on page 11-22. The Temperature and Oil pressure sensors are normally open and close (connect to the engine ground) when high temperature or low oil pressure is sensed.
This in not how to design a failsafe system but that is how they were made. If you have the original alternator, the charge alarm is activated when the alternator sense terminal “L” voltage is less then the battery voltage. The alarm buzzer will come on when ever anyone of the three alarms lights are on.
You should be able to trouble shoot it without running the motor. The oil and charge lights should come ON along with the buzzer when you turn on the key switch. Locate the oil sensor and pull off the connector and the low oil lamp should go OFF. Locate and ground the water temperature sensor and the high temperature lamp should go ON. The charge light is more difficult to check and you have to be careful not to short or open circuit the alternator or the internal voltage regulator or diodes may be damaged. Read the manual. I can email you a copy if you don’t have one.
The key switch only enables the starter switch and the alarm circuit. I strongly recommend that you never operate the motor without the key switch ON or the alarm circuit will be disabled and you would not know if the motor overheats or looses lubricating oil and can result in destroying the motor.
My boat’s home is just around the corner at T-Bird Marina. I think your Yamaha 30 is similar to a Yamaha 25 where the motor is mounted under the V-berth and you probably have an YSM-12.
Based on your description, I suspect there is an intermittent wiring problem in the alarm circuit. Check the wiring harness and sensor connections. The alarm circuits are described in my YSM-12 manual in Chapter 11 (electrical) Section 5, starting on page 11-22. The Temperature and Oil pressure sensors are normally open and close (connect to the engine ground) when high temperature or low oil pressure is sensed.
This in not how to design a failsafe system but that is how they were made. If you have the original alternator, the charge alarm is activated when the alternator sense terminal “L” voltage is less then the battery voltage. The alarm buzzer will come on when ever anyone of the three alarms lights are on.
You should be able to trouble shoot it without running the motor. The oil and charge lights should come ON along with the buzzer when you turn on the key switch. Locate the oil sensor and pull off the connector and the low oil lamp should go OFF. Locate and ground the water temperature sensor and the high temperature lamp should go ON. The charge light is more difficult to check and you have to be careful not to short or open circuit the alternator or the internal voltage regulator or diodes may be damaged. Read the manual. I can email you a copy if you don’t have one.
The key switch only enables the starter switch and the alarm circuit. I strongly recommend that you never operate the motor without the key switch ON or the alarm circuit will be disabled and you would not know if the motor overheats or looses lubricating oil and can result in destroying the motor.
Jalepeno; looks like I cant post my email address on here. We dont have an oil light. But I'll carry out the temp sensor test. Problem is that it is intermittant. And the weird thing is that it was the temp light first then the charge light later. Weve had Keith from Howe sound marine round twice and its getting a bit expensive! But I dont feel comfortable going anywhere serious without this diagnosed and fixed. Had a similar problem in our car - turned out to be a grounding problem with the alternator - wondering if I should replace the alternator (its not original)
You definitly do not turn the ignition off when the engine is running, it will burn out the diodes in the alternator. (may be your problem) You should first check the belt tension. A loose belt can cause the alternator to slip when under load. It also can let the pully on the water pump slip, thus not circulating cooling water enough allowing an overheat. Finally make sure your wiring harness is not chaffed on a sharp turn, grounding any part of the sensor wiring. You should have your alternator tested for a open or shorted diod. This can be done at no cost at most auto parts stores.
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