What is causing this alarm on my Honda O/B?'

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DaveC426913
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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Wed Aug 19, 2020 12:54 pm

Will check that next time.
MacX 2000 Honda BF50A 'SeaSaw'

DaveC426913
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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Fri Aug 21, 2020 4:41 pm

OK, I checked out the oil pressure light.

It comes on just a few seconds after the motor starts and stays on.

The second time I tried it, after going out for a spin, it did not come on at all.

Image
MacX 2000 Honda BF50A 'SeaSaw'

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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Wed May 19, 2021 10:50 am

Still trying to track this down. Am stumped.

Working theory: shop manual and most reports state that the constant alarm occurs under the following conditions:

ignition key on - AND - one or both of:
- low or no oil pressure
- over temperature

When in ignition or on,Oil Pressure light on remote is lit, Oil Temp light is not lit.

We
- located the temp and oil pressure senders on the engine
- disconnected either/both sensor leads does not shut off the alarm. First nail in theory's coffin
- shorting either sensor lead to engine block - no difference
- the oil pressure sender was tested with engine running; it went open, which is proper operation

Suggestions as to next steps?
MacX 2000 Honda BF50A 'SeaSaw'

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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Mon Jul 12, 2021 12:41 pm

Having checked the functionality of the oil and pressure sensors, my friend suggests we open the pedestal remote control and check the circuitry there.

My question:
for the alarm buzzer to buzz, it needs power obviously. It must come from one of two places, either:
  • the remote gets its power from the electrical system on the motor, or
  • the remote control has its own power directly from the battery.
If 1, then any fault must be in the electrical system of the motor, not in the remote. There would be nothing that could go wrong in the remote that could cause it to get power. It could only lose power.

Anyone know if the pedestal remote has its own power?
MacX 2000 Honda BF50A 'SeaSaw'

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Re: What is causing this alarm on my Honda O/B?'

Post by Be Free » Tue Jul 13, 2021 7:52 am

The remote gets power and ground from the cable connecting the engine to the remote. The engine is connected to the boat's electrical system through the two large wires.
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Re: What is causing this alarm on my Honda O/B?'

Post by Be Free » Tue Jul 13, 2021 9:58 am

DaveC426913 wrote:
Wed May 19, 2021 10:50 am
Still trying to track this down. Am stumped.

Working theory: shop manual and most reports state that the constant alarm occurs under the following conditions:

ignition key on - AND - one or both of:
- low or no oil pressure
- over temperature

When in ignition or on,Oil Pressure light on remote is lit, Oil Temp light is not lit.

We
- located the temp and oil pressure senders on the engine
- disconnected either/both sensor leads does not shut off the alarm. First nail in theory's coffin
- shorting either sensor lead to engine block - no difference
- the oil pressure sender was tested with engine running; it went open, which is proper operation

Suggestions as to next steps?
I'm going by the 2003 schematic posted earlier. If your manual is different, please post and I'll reassess.

The schematic shows that the oil pressure (and temperature) switches are NO (normally open). The schematic also shows that the switch is in the ground wire for the circuit. By convention, pressure switches are diagrammed in their normal position when they are not "excited". The diagram shows that the pressure switch breaks a ground connection when there is no or low oil pressure and it provides a ground when there is pressure.

Because the switches are NO, disconnecting the leads will never turn off the oil pressure alarm and will always turn off the temperature alarm. Open is a fault condition on the oil pressure switch but closed is the fault condition on the temperature switch.

This means that if you ground the wire on the pressure switch while the key is on the oil light light will come on and the alarm will stop. According to your test grounding the switch did not turn off the alarm (unclear about the light condition at this point).

According to the schematic the switch should CLOSE while the engine is running. Your test indicated that it went open.

If you manually connect the oil pressure switch to the block of the engine (what the switch should be doing under normal conditions) and the alarm does not go off then it's possible that you are losing your ground connection between the engine and the remote.
Bill
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Re: What is causing this alarm on my Honda O/B?'

Post by Starscream » Tue Jul 13, 2021 2:02 pm

Not having read the previous 4 pages of posts, have you checked the tilt-sensor alarm? The Honda will sound a continuous buzz when the motor is tilted by a certain angle and power is above a certain min.

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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Wed Jul 14, 2021 4:27 pm

Starscream wrote:
Tue Jul 13, 2021 2:02 pm
Not having read the previous 4 pages of posts, have you checked the tilt-sensor alarm? The Honda will sound a continuous buzz when the motor is tilted by a certain angle and power is above a certain min.
Indeed. We checked that today. Made no difference.
MacX 2000 Honda BF50A 'SeaSaw'

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Re: What is causing this alarm on my Honda O/B?'

Post by DaveC426913 » Wed Jul 14, 2021 4:39 pm

Today we* verified with a meter that the oil pressure sender, oil temp sender, oil pressure warning light, oil temp warning light are all operating as per spec. And that the tilt sensor had no effect on the alarm (I've never heard it).

The *only* thing not operating per spec is the buzzer itself. We* presume the fault lies in the ignition circuit. So we* inserted a connector in the buzzer line so that at least me and the Mate don't drown ourselves on the five-hour outbound leg of our upcoming cruise.

I'll have to check oil temp and presh manually until we find a permanent fix.

*and by "we", I mean my "marine mechanic friend", while I sat in the shade and joked about why he was reverse-cow-girling my boat.


(My friend told me was getting most of his Honda intel from a site called macgregorsailors.com and recommended I check it out. :) )
MacX 2000 Honda BF50A 'SeaSaw'

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