What is this relay for
- Thread starter timjet
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mahal
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So I would be supplying power to whatever the relay is connected to bypassing any switch or control circuit to whatever the relay is connected to.
Yes??
You got it.
You are probably right that it has to do with the engines as there are two relays. Are the lights for your engine gauges working? I know it is hard to trace the wires, especially to the load side but how about tracing the switch side (#86). Does it go to your ignition switch? Just a thought.
Andy G
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A very slight hijack.
Is that wiring colour code an international code? That is, could I rely on it for my Hong Kong built Island Gypsy? Or for that matter any of the other Asian built boats.
Moonstruck
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Tim, just a thought, but since the Carver was offered with both gas and diesel engines do you think the wiring harness was also set up for gas engines. The relays could be for that.
sunchaser
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Many have disconnected pre heaters on Cummins engine starts, maybe the PO or factory did same. On my engines the relays like yours protect all the engine start circuits such as stop solenoid, neutral safety switch, fuel heating grid and two others I can't remember.
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timjet
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No, the new one is not either
Don't be sorry. The fuses are blown, so it's not likely someone disabled these 2 circuits on purpose. These circuits power something and they are suppose to be working.
It will probably be impossible to trace these wires, but there is a purple wire and according to the wiring color chart purple goes to the ignition or instrument panel. That's a start.
Yes, both work normally
Yes Carver did probably set up the wire harness's for gas and modified my diesel version as needed. I've seen several wire bundles with connectors connected to nothing. The problem is the fuses are blown which indicates to me that the relays powered something at one time.
My knowledge of the electrical system on my engines is limited (because I haven't had a problem with that system) so it could be something with the engines. Especially since there is no switch in the circuit. All other items in the Battery Switch CB panel are switched. All items on my engines run normally, neutral safety switch, solenoid stop. The electric pre-heat worked on the port engine back in November when I had a re-man engine installed. The installer noted the voltage drop on the batteries and brought it to my attention.
But again the fuses are blown indicating to me that these circuits were not intentionally disconnected.
I installed the oil change pump and wired it though a different CB panel protected by a CB. The autopilot works fine. However I do have a reversible fuel transfer pump wired through the same CB panel as the oil change pump and protected by a CB. I haven't used it in some time and I doubt that's it but will check next time I'm at the boat.
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timjet
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My thanks to everyone who's stuck with me so far on this. Some really great ideas and info has been presented.
Maybe I should start another thread, but there is one thing I don't understand and likely has nothing to do with this issue. I don't understand how the engine alternators are connected to the batteries.
Using my digital volt meter I've determined that the voltage output from both alternators are directed to the battery bank selected on the battery switch. It doesn't matter which engine is running or both running the alternator output current is directed to the battery bank selected on the battery selector switch. However in looking at the battery selector switch CB panel I see no wiring from the alternators. The alternators are around 100 amp units and this would require #2 battery cables. There is nothing like that in the CB box. I understand the alternator output may not be wired through this CB box, but if it isn't how would the alternator output be directed by the battery selector switch?
Two reasons I don't think the blow fuses and the associated circuity has anything to do with directing alternator output.
1. It works, alternators functioned as described last time we were on the boat.
2. The two blown fuses are connected to the same pole on the battery selector switch.
Maybe I should start another thread, but there is one thing I don't understand and likely has nothing to do with this issue. I don't understand how the engine alternators are connected to the batteries.
Using my digital volt meter I've determined that the voltage output from both alternators are directed to the battery bank selected on the battery switch. It doesn't matter which engine is running or both running the alternator output current is directed to the battery bank selected on the battery selector switch. However in looking at the battery selector switch CB panel I see no wiring from the alternators. The alternators are around 100 amp units and this would require #2 battery cables. There is nothing like that in the CB box. I understand the alternator output may not be wired through this CB box, but if it isn't how would the alternator output be directed by the battery selector switch?
Two reasons I don't think the blow fuses and the associated circuity has anything to do with directing alternator output.
1. It works, alternators functioned as described last time we were on the boat.
2. The two blown fuses are connected to the same pole on the battery selector switch.
Tom.B
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Are you sure the alternator runs THROUGH the selector switch? My alternator was originally connected directly to the battery via the positive stud on the starter. In other words, it was wired, somewhat, directly to the start battery. I have since wired it directly to the house bank with a nice fat wire. Now, I say that to say this --- The selector switch in OUR breaker panel only selects only what SOURCE the DC side of the panel is powered (house, start, both, off) and doesn't direct charging at all. Certainly, yours is different, but I offer it up just to show you how it MIGHT be wired.
(If you look at the pics of my project above, all relays are wired to a positive source. The way relays work, as I am sure you know, is so that small voltage switch can toggle a much larger switch. The wires from your selector switch are probably feed the larger switch side and was likely just a convenient (nearby) power source. That's my theory anyway. It REALLY sounds like you just need to trace wires to know for sure.)
(If you look at the pics of my project above, all relays are wired to a positive source. The way relays work, as I am sure you know, is so that small voltage switch can toggle a much larger switch. The wires from your selector switch are probably feed the larger switch side and was likely just a convenient (nearby) power source. That's my theory anyway. It REALLY sounds like you just need to trace wires to know for sure.)
LaBomba
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TimJet, not sure if this one has been mentioned. On my single I have to push down on my ignition switch for glow plug activation and then turn to start. Both go through relays the same as you are showing. You say your engines are running normally but are your glow plugs actually working?? Just a thought.
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timjet
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That could be and probably is the way it's wired. The Feeder pole on the battery selector switch does have a cable running to each engine.
Thanks
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timjet
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Not really, they were taken over by another company but still building boats under the Carver name. They still do offer support and I will be contacting them.
I need to re-read and think about what you wrote for a bit.
No glow plugs on my Cummins 6BT 330 AT-M3's.
But I think maybe this is the right track. Who ever wired this and I believe it's original from the factory, wired it hot to a battery. There must be a reason for this as there is nothing else hot wired to any battery that is not on a switch.
The circuit feeding the coil must be protected as well.The fused wires that come from your battery selector switch, probably are feeding the high-current side of the relay...
(Does that help?)
Wxx3
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Or you can also trace the source wire, not the ground or the fuzed one, but the one that powers the coil on the relay.
Could be some pre-ignition circuit, connected to glow plugs??
Could be some pre-ignition circuit, connected to glow plugs??
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timjet
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I haven't been to the boat since starting this thread so haven't been able to accomplish some of the suggestions. But a thought came to me, could these relays have any thing to do with the fire suppression unit which I believe if activated will shutdown the engines?
RT Firefly
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The relays could be for a couple dozen different things. It's all speculation from this end. You have to trace the wires. You don't have to physically trace them, there are electronic devices that will help. Also, the color of the insulation helps with tracing.
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timjet
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Mystery solved
I contacted Carver and they solved the mystery. The relays start the bilge blowers when the ignition switch is turned on. There are 2 blowers hence 2 relays. There is a manually operated blower switch on the helm that I always turn on before I start the engines and why I didn't suspect the blowers. A nice feature I guess but redundant since I'm able to remember to turn them on manually.
Turning them on manually perhaps blew the fuses.
This feature is installed on diesel versions only.
I contacted Carver and they solved the mystery. The relays start the bilge blowers when the ignition switch is turned on. There are 2 blowers hence 2 relays. There is a manually operated blower switch on the helm that I always turn on before I start the engines and why I didn't suspect the blowers. A nice feature I guess but redundant since I'm able to remember to turn them on manually.
Turning them on manually perhaps blew the fuses.
This feature is installed on diesel versions only.
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I'm assuming gasoline engines.
Not that great a feature. The blowers are supposed to be turned on four minutes (more or less) before starting the engine(s). Starting is one of the greatest risks of sparks and any gasoline fumes should be evacuated before you start the engines, not when you start them.
Do the blowers shut off automatically? Why are the fuses blown?
psneeld
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It's a diesel boat (Cummins Engines - in his signature) and I've heard some diesel engine manufactures won't approve new boat installs if there's not enough air volume in the engine room and/or enough open air vents so they require the engine room to be power ventilated.
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If that's the case they would have to blow air into the engine room, not out of it as with a gasoline engine.
And the blowers would have to run continually when the engines are running.
Perhaps another call to the manufacturer is in order.
psneeld
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The blowers could be rigged either way to satisfy requirements...I don't know about his setup...but I DID know he had diesels because I pay close attention to what I read....in fact I pay CLOSE attention In life in general.
If they come on when the ignition switch is turned on...good chance they DO run all the time the engines are on...thus the reason why the manufacturer used them in the first place...
Blowers on diesel boats are really often just to make sure you have air turnover so the air in the engine room contains cool enough air for the diesels to retain optimum performance.
Whether they suck or blow doesn't matter as long as the engine is happy...but that's not my area of expertise....
If they come on when the ignition switch is turned on...good chance they DO run all the time the engines are on...thus the reason why the manufacturer used them in the first place...
Blowers on diesel boats are really often just to make sure you have air turnover so the air in the engine room contains cool enough air for the diesels to retain optimum performance.
Whether they suck or blow doesn't matter as long as the engine is happy...but that's not my area of expertise....
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The blowers could be rigged either way to satisfy requirements...I don't know about his setup...but I DID know he had diesels because I pay close attention to what I read....in fact I pay CLOSE attention In life in general.
If they come on when the ignition switch is turned on...good chance they DO run all the time the engines are on...thus the reason why the manufacturer used them in the first place...
Blowers on diesel boats are really often just to make sure you have air turnover so the air in the engine room contains cool enough air for the diesels to retain optimum performance.
Whether they suck or blow doesn't matter as long as the engine is happy...but that's not my area of expertise....
If you want more air in a container, you blow it in and pressurize it.
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