Good read for anyone with electrical woe's

[mosquito13]

www.melody-in-blues.org/downloads/electrical_12volthandbook.pdf

[Simple Man]

Nice, thanks. I've got it in my iBooks library now!
Let me share something I learned yesterday that I had never really thought about before.
A DC positive power source must be grounded back to the same negative source. In other words if you pull a positive wire off of battery "A" and try to ground it to the negative side of battery "B", it won't work.
I was trying to fix some small issues that didn't get put back right after my engine swap. One of them is constant power to my radio so it doesn't lose its settings. Tried to pull the power from a trolling motor battery in the console. No go. Had to pull a wire from the back cranking battery. Big fun.

[Juan]

Jan 21, 2018 8:31:57 GMT -6 Simple Man said:

Nice, thanks. I've got it in my iBooks library now!
Let me share something I learned yesterday that I had never really thought about before.
A DC positive power source must be grounded back to the same negative source. In other words if you pull a positive wire off of battery "A" and try to ground it to the negative side of battery "B", it won't work.
I was trying to fix some small issues that didn't get put back right after my engine swap. One of them is constant power to my radio so it doesn't lose its settings. Tried to pull the power from a trolling motor battery in the console. No go. Had to pull a wire from the back cranking battery. Big fun.

I had thee same problem with my engine swap.. they didn't connect the radio, the bow trim switch and had the trim tabs connected in reverse. Question: Do you turn your battery selector switch to off when it's going to sit on the lift? If so, doesn't that kill the power to the radio and you lose the preset channels? or do you have a connection that stays hot even when the battery selector switch is in the off position and if that's the case, I know it's not much, but isn't it draining the battery? I ask because I lose all the preset channels when I turn the selector switch to off.

[Simple Man]

Yes,I kill the main now and all power was cut when I killed the battery switch, that was the issue because like you I would lose my settings. That bugs me so I had to fix it. There is a constant power wire on I guess most all radios that supply this power to keep the settings. I assume it drains the battery some but it is an insignificant amount of draw and has never been noticeable in the past.

[Juan]

So I guess I'll have to move the wire that powers my radio from the selector switch and connect it to a constant power source to save the preset radio channels. I know the power draw would be small but I'm not crazy about having anything constantly drawing power (other than the bilge pump). I hardly use the radio stations any way and usually play music form the SD card or a flash drive. I wish the radio had a internal battery that saved the channels but it doesn't. Don't you worry about the constant power shorting out? Your boat could end up a crispy critter like your last one.

[yolo]

Jan 21, 2018 8:31:57 GMT -6 Simple Man said:

Nice, thanks. I've got it in my iBooks library now!
Let me share something I learned yesterday that I had never really thought about before.
A DC positive power source must be grounded back to the same negative source. In other words if you pull a positive wire off of battery "A" and try to ground it to the negative side of battery "B", it won't work.
I was trying to fix some small issues that didn't get put back right after my engine swap. One of them is constant power to my radio so it doesn't lose its settings. Tried to pull the power from a trolling motor battery in the console. No go. Had to pull a wire from the back cranking battery. Big fun.

If batt a and b are not connected in parallel then what you found is correct it wont work. Its has to be powered and grounded to the same source/battery/bank. The radio is grounded to the battery or battery bank (not sure what you have) thats grounded to the verado. The trolling motor is its own grounding point.

But doesn't your trolling motor bank put out more than 12v?

[yolo]

Jan 22, 2018 7:09:43 GMT -6 Simple Man said:

Yes,I kill the main now and all power was cut when I killed the battery switch, that was the issue because like you I would lose my settings. That bugs me so I had to fix it. There is a constant power wire on I guess most all radios that supply this power to keep the settings. I assume it drains the battery some but it is an insignificant amount of draw and has never been noticeable in the past.

Yeah all the radios have the memory wire. Its yellow out of the harness. Assuming wired correct from the harness just take the accessory wire off the switch and put it on the battery. And exactly what you said its so insignificant. This is how they are wired from the factory with factory radio installs.

If you need to figure out at the switch which one is the memory wire. Grab your multi meter and if you cant reach from where the radio is to where the 12v battery bank is then grab a set of aligator clips from the electrical connector section at home depot or lowes or any other hardware store. Length of wire you would need to extend the gap. Attach alligator clips to each end. Put one on the multi-meter lead. Clip the other to the first lead you want to test (should be one of the smaller wires there). Poke the yellow wire with the test lead and see if you have continuity. If nothing move the clip onto the next lead behind the switch.

[yolo]

Jan 19, 2018 7:48:27 GMT -6 mosquito13 said:

www.melody-in-blues.org/downloads/electrical_12volthandbook.pdf

This is a great share. Goo explanations and examples. Nice find.

[Simple Man]

I was basically reinstating what was not put back in the transition from a Merc wiring harness to a Yamaha one so wiring was easy. I just had to pull a new wire once my first plan didn't work. I'm not worried about the constant powered wire or the mili-amp draw. It's been hot and drawing power since 2008 plus the new wire is fused so it should be all good.

[yolo]

Jan 22, 2018 21:42:19 GMT -6 Simple Man said:

I was basically reinstating what was not put back in the transition from a Merc wiring harness to a Yamaha one so wiring was easy. I just had to pull a new wire once my first plan didn't work. I'm not worried about the constant powered wire or the mili-amp draw. It's been hot and drawing power since 2008 plus the new wire is fused so it should be all good.

Missed that you were already done the first time I read through. My bad.

Ive got mine wired up same as you.

[yolo]

Jan 22, 2018 21:42:19 GMT -6 Simple Man said:

I was basically reinstating what was not put back in the transition from a Merc wiring harness to a Yamaha one so wiring was easy. I just had to pull a new wire once my first plan didn't work. I'm not worried about the constant powered wire or the mili-amp draw. It's been hot and drawing power since 2008 plus the new wire is fused so it should be all good.

lol and i have no clue why my font goes orange whenever I respond to you lolol

[Juan]

Jan 22, 2018 23:58:25 GMT -6 yolo said:

lol and i have no clue why my font goes orange whenever I respond to you lolol

I have yet to figure that out too. It's an Auburn thing. 021

[985crabs]

Thanks Skeeter. This is a great resource for someone like me who understands only the very basics of electricity, like don't touch the wires when they're hot.

[yolo]

Jan 23, 2018 6:20:56 GMT -6 Juan said:

Jan 22, 2018 23:58:25 GMT -6 yolo said:

lol and i have no clue why my font goes orange whenever I respond to you lolol

I have yet to figure that out too. It's an Auburn thing. 021

LOL!