Is this ON switch momentary? Doesn't sound right.... The START and STOP should be momentary.
1997 420 AC Gas Westerbeke question
- Thread starter Fred Freitag
- Start date
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
I hold down the on switch and the fuel pump starts. The I continue to hold down the on switch and press down the start switch. The gen starts and I hold the on switch for another couple seconds until the oil pressure comes up then I release the on switch. Gen runs until I hold the stop switch down
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
I should have taken a video showing the start sequence from the gen panel and then the salon panel. Didn't think about that when I was on the boat. 
mrsrobinson
Well-Known Member
@Fred senesi prefix the @ symbol in front of a member's name if you want to reference them in a reply.
Yes I think a video from the salon switches would help at this point.
Yes I think a video from the salon switches would help at this point.
370Dancer
Well-Known Member
- Oct 2, 2006
- 2,489
- Boat Info
- 1998 370 Sundancer
- Engines
- 380hp MAG MPI Gen VI with V drives
I'd like to know exactly what model of generator you have. Can you find the label, or has it been painted over/removed?
If you can momentarily hit the start button, and stuff is happening, (slow blink becomes fast blink), then you have other circuitry controlling the start sequencing.
If you can momentarily hit the start button, and stuff is happening, (slow blink becomes fast blink), then you have other circuitry controlling the start sequencing.
370Dancer
Well-Known Member
- Oct 2, 2006
- 2,489
- Boat Info
- 1998 370 Sundancer
- Engines
- 380hp MAG MPI Gen VI with V drives
My research says you have a 9.0BTG. You MAY have a newer genset that replaced the original. I think that's the mystery right now. The remote panel for a 9.0 BTG is a 3 switch arrangement.
Do you have your bilge blowers turned on before starting the genset, and leave them on? They appear to be related in the panel diagram of the parts manual. You are going to need these if you don't already have them. Here you go.
the genset manual is too big. Just do a search for a 9.0 BTG Westerbeke, if that is indeed what you have.
Do you have your bilge blowers turned on before starting the genset, and leave them on? They appear to be related in the panel diagram of the parts manual. You are going to need these if you don't already have them. Here you go.
the genset manual is too big. Just do a search for a 9.0 BTG Westerbeke, if that is indeed what you have.
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
@370Dancer - from the survey document it looks like a 9.0BTG serial number 28324
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
techmitch
Well-Known Member
- May 1, 2008
- 8,396
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- 1999 270 DA
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- Twin 4.3s W/Alpa I Gen II's
Do you know if it is the original generator? I was going to ask early in the thread but got distracted then lost the thread.
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
There is no reason for me to think it's not the original generator.
370Dancer
Well-Known Member
- Oct 2, 2006
- 2,489
- Boat Info
- 1998 370 Sundancer
- Engines
- 380hp MAG MPI Gen VI with V drives
Find the ID tag if you can. There is a lot of conflicting info floating.
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
I've only seen the Monoplex controllers on diesel generators so that's new to me.
On these Westerbeke generators there is a sensor loop where if one of more of the sensors go out of range the generator shuts down. All of the sensors are normally closed except for the oil pressure. So, there has to be a bypass of the sensor loop to allow the generator to start and the oil pressure to come up to close the electrical conductivity through the loop.
Typically, when the engine start initiates that sensor loop is automatically bypassed then when the start button is released and oil pressure is up the sensor loop is put back in the ignition circuit (for diesel the fuel solenoid circuit).
Normally I'd say there is an issue the sensor loop or the relay that controls the loop. However, the generator local start works just fine which says the sensor loop is good. All of this is for the older analog generators and not applicable to the CPU controlled ones.
Another interesting aspect is the Monoplex is a Sea Ray added feature for remote start and not OEM from Westerbeke. The question is - does that Remote switch functionally bring the Monoplex in the control of the generator?
On these Westerbeke generators there is a sensor loop where if one of more of the sensors go out of range the generator shuts down. All of the sensors are normally closed except for the oil pressure. So, there has to be a bypass of the sensor loop to allow the generator to start and the oil pressure to come up to close the electrical conductivity through the loop.
Typically, when the engine start initiates that sensor loop is automatically bypassed then when the start button is released and oil pressure is up the sensor loop is put back in the ignition circuit (for diesel the fuel solenoid circuit).
Normally I'd say there is an issue the sensor loop or the relay that controls the loop. However, the generator local start works just fine which says the sensor loop is good. All of this is for the older analog generators and not applicable to the CPU controlled ones.
Another interesting aspect is the Monoplex is a Sea Ray added feature for remote start and not OEM from Westerbeke. The question is - does that Remote switch functionally bring the Monoplex in the control of the generator?
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
I think the remote switch "triggers" functions in the Monoplex controller. First press activates the fuel pump signified by the slow flashing light then rapid flash after 10-15 seconds. Then the second press activates the starter. And like you hypothesized in your previous post possible the third press activates the shutdown? One thing is for sure...the Monoplex pigtail that plugs into the gen harness has 6 wires and the harness that connects to the remote salon switch has 3. I wish I had the circuit layout of the Monoplex controller to see what it is doing or better yet just have one to plug in and see if that is the problem.
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Stee6043
Well-Known Member
Hmm - your setup may not be stock anymore. Based on the DIY red paint job, the loose/bent side cover on the generator control panel and the way the onboard switches are configured (not straight) - I'd bet a jr bacon cheese burger that your generator was molested by a prior owner.
I also found 2 gas powered 420 AC's of your vintage on boat trader that both listed 8KW Beke's. Furthering confusion...
I also found 2 gas powered 420 AC's of your vintage on boat trader that both listed 8KW Beke's. Furthering confusion...
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
It definitely looks like someone has been inside the box on the gen. I compared all of the wiring inside and it checks out with the schematic. I do think the generator is original to the boat. The previous owner has all of the boat documentation from when it was delivered new and the schematic that came with the boat was the Weterbeke 9.0BTG.
370Dancer
Well-Known Member
- Oct 2, 2006
- 2,489
- Boat Info
- 1998 370 Sundancer
- Engines
- 380hp MAG MPI Gen VI with V drives
Now I'd call Sea Ray and ask them who installed the Monoplex. I don't think Westerbeke would have allowed that unit to block the ventilation of the back end. And, if you have the ability, as the PO what their startup/shutdown procedure is. Me thinks an overzealous somebody, who was apprehensive about a gas genset went to extra lengths to incorporate what is normally found on the diesel units. So, as Mr. Wonderful would say, "I'm out."
Good luck with solving the mystery.
Good luck with solving the mystery.
Fred Freitag
Member
- Jul 8, 2023
- 30
- Boat Info
- 1997 Searay 420 Aft Cabin
- Engines
- Mercruiser 7.4 MPI
@370Dancer - I appreciate your help! I will update the thread once I get to the bottom of this...if ever!
I'm curious to know the outcome too.
The "monoplex" box is just to simplify the operation and make what would be a multi-button timed operation a single button function. In my mind, that console switch should be a regular on-off, not a momentary. It would enable the monoplex box, which would cycle the appropriate relays (taking the place of the three switches) to enable, prime, and start the generator. You would simply flip the switch "on" to start the process, then switch it back to "off" to shut the generator down. Why it's a momentary and requires multiple pushes is confusing and I would think would cause many boat owners frustrations. That's why they use things like a monoplex.
It's possible that the problem is within the monoplex. There might be a time-delay process that's supposed to keep one relay closed long enough for oil pressure to be established, then "time out" and open and let the oil pressure switch take over. If the time-delay was supposed to be, say, 15 seconds and is now zero then the genset would shutdown prior to the oil pressure switch activating. you could temporarily bypass that switch to test if that's what's happening.
The "monoplex" box is just to simplify the operation and make what would be a multi-button timed operation a single button function. In my mind, that console switch should be a regular on-off, not a momentary. It would enable the monoplex box, which would cycle the appropriate relays (taking the place of the three switches) to enable, prime, and start the generator. You would simply flip the switch "on" to start the process, then switch it back to "off" to shut the generator down. Why it's a momentary and requires multiple pushes is confusing and I would think would cause many boat owners frustrations. That's why they use things like a monoplex.
It's possible that the problem is within the monoplex. There might be a time-delay process that's supposed to keep one relay closed long enough for oil pressure to be established, then "time out" and open and let the oil pressure switch take over. If the time-delay was supposed to be, say, 15 seconds and is now zero then the genset would shutdown prior to the oil pressure switch activating. you could temporarily bypass that switch to test if that's what's happening.
