Problem with ACR

Brian,
Yes, long before the stereo starts to cut out the audio performance really begins to suffer due to low voltage. The best solution for any towboat is to start with highly efficient amplifiers, like fullrange Class D for example.
A Class AB amplifier will consume 2000 supply watts to produce 1000 watts of audio output. 1000 watts is wasted in heat generation.
A Class D amplifier will consume 1250 supply watts to produce 1000 watts of audio output. 250 watts is wasted in heat generation.
The Class AB converts 400 percent more supply to wasted heat at the same output level than a Class D.
Problem solved and no need for an upgrade alternator. Plus, when you lift the observers seat it won't feel like a blast furnace coming out of the port locker in July and August.

David
Earmark Marine

So I finally figured out what the issue is with my ACR. To restate the problem, the ACR will not combine with the engine running as indicated by a blinking green light. I tracked the problem down to the Starter Isolation circuit. The ACR has an optional SI wire that should be connected to the ignition switch, specifically, to a post on the switch that shows zero volts when in the on position and 12 volts when the engine is being started. I thought that was the post on the ignition switch that the yellow wire with the red stripe is connected to so this is where I connected my SI wire. The SI feature momentarily disconnects the batteries (when they are in a combined state) when the engine is started so that the stereo equipment is not affected by the surge in current required to start the engine.

What I found is that the post on the ignition switch where I had the SI wire connected does indeed show zero volts when in the on position and 12V when in the "engine start" position. HOWEVER, I discovered that as soon as the engine is put into gear, the post shows 12V. So that is why it was combining when the engine was running but the throttle is in the neutral position but would not combine when I was underway. I checked the other two posts on the ignition switch and both show 12V when the key is in the on position.

So I concluded that at least on my boat, there is no way to use the SI feature so the SI wire should not be connected.

Razz/Mandley,

Please check your ACR's since I think you wired your SI the same way I did and let me know if the green LED is blinking when your engine is running and the transmission is in gear.

Thanks,

Al

So last time out i didn't see mine come on either. theres gotta be an ignition wire to connect to. wonder if SC can help with this one?

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Originally Posted by Razzman

So last time out i didn't see mine come on either. theres gotta be an ignition wire to connect to. wonder if SC can help with this one?

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Razz, did the LED not come on at all or was it blinking green?

When I have time, I will pull out the ignition switch and see if there are another spades there that might not be in use. Just have to find one that is zero volts all the time except when the key is turned to the start position.

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Originally Posted by cab13367

Razz, did the LED not come on at all or was it blinking green?

When I have time, I will pull out the ignition switch and see if there are another spades there that might not be in use. Just have to find one that is zero volts all the time except when the key is turned to the start position.

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I didn't notice any activity, but then I wasn't staring at it either.

starter relay? what ever activate the starter solenoid should give you exactly what you are looking for.

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Originally Posted by rdlangston13

starter relay? what ever activate the starter solenoid should give you exactly what you are looking for.

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Good point. I guess I could trace the wire coming from the ignition switch to try and find the starter relay that way. I just don't want to have to pull the sub box out and there's very little room under the dash unless I do so. Or is it at the starter? I may just leave the SI wire disconnected. Can anyone comment on the importance of having a starter isolation relay in place?

It's puzzling to me though why that post on the ignition switch would show 12V when the transmission is in gear. What purpose does that serve?

Quote:

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Originally Posted by cab13367

Good point. I guess I could trace the wire coming from the ignition switch to try and find the starter relay that way. I just don't want to have to pull the sub box out and there's very little room under the dash unless I do so. Or is it at the starter? I may just leave the SI wire disconnected. Can anyone comment on the importance of having a starter isolation relay in place?

It's puzzling to me though why that post on the ignition switch would show 12V when the transmission is in gear. What purpose does that serve?

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Al the isolation is there i believe to insure that only the starting battery is tapped when starting.

edit: Here's what Blue Seas literature says;

• Automatically combines batteries during charging, isolates batteries when discharging and when starting engines
• Allows temporary isolation of house loads from engine circuit during engine cranking to protect sensitive electronics—starting isolation indicated by blinking LED

Quote:

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Originally Posted by Razzman

Al the isolation is there i believe to insure that only the starting battery is tapped when starting.

edit: Here's what Blue Seas literature says;

• Automatically combines batteries during charging, isolates batteries when discharging and when starting engines
• Allows temporary isolation of house loads from engine circuit during engine cranking to protect sensitive electronics—starting isolation indicated by blinking LED

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Razz,

I get this. And the way this happens is that when the ACR senses 12V+ coming in thru the SI wire, the relay opens, disconnecting the batteries. As soon as the 12V+ goes away, it closes again. The problem is that when you put the boat in gear, 12V+ is sent to the ACR again via the SI wire so the relay opens. So any time the engine is running and the boat is in gear, the ACR is open and the batteries are isolated, which is not what we want.

What I meant by my question, "What purpose does it serve?" is the 12V+ at the ignition switch when the boat is placed in gear.

Al

Something is amiss here guys-

If your ignition cranking send wire, (ABYC and USCG yellow with red stripe) goes to +12 with the motor running, your starter will be cranking while the motor is running!

If indeed you really go to 12v positive in gear, there is a starter interrupt relay somewhere between the ignition switch and the starter relay. Move your SI wire to either that relay's output to the starter solenoid, or take it directly to the positive lug of your starter as a means of last resort.


I do agree the SI wire is likely not necessary on your boat(s) but there is a way to get the SI circuit working properly....

Phil
Kicker