12 Volt DC Wiring

I reconnected the wiring harness to the new slide relay, then reinstalled the slide motor and the slide works like a charm now...In and Out! Yahooo! Thanks everyone for your contributions to solving my issue. I hope to someday reciprocate. All my best.

Sully2 wrote:


But the wire gauge required would be dependant upon how many amps the relay pulled to operate. So with that being why does a relay require as much as 30 amps when its controlling circuits powered by 18 gauge wiring??????

I can't answer that question as I didn't mfg the relay. Reading the instructions from the mfg, it specifies 10AWG wire must be used. I believe the OP was changing the OEM relay to the newer, maybe more robust one, hence my caveat....Dennis

Executive wrote:

Sully2 wrote:

Executive wrote:
Make sure you use 10AWG wire for the relay....Dennis

Are you kidding? 10 ga will carry 30 amps. This gentleman is talking THREE AMPS

Read it again, Sully.....wiring for the RELAY must be 10AWG. For the SWITCH it can be 18AWG.....:W....Dennis

The load side of the relay is already wired and doesn't need any changing. According to the instructions he just needs to change the common connection on the switch to 12 volts DC fused for 3amps. The only wire he needs to add is at the switch. Depending on where it is currently grounded, it's possible he could move the other end of the wire from ground to 12 volts.

Executive wrote:

Sully2 wrote:

Executive wrote:
Make sure you use 10AWG wire for the relay....Dennis

Are you kidding? 10 ga will carry 30 amps. This gentleman is talking THREE AMPS

Read it again, Sully.....wiring for the RELAY must be 10AWG. For the SWITCH it can be 18AWG.....:W....Dennis

But the wire gauge required would be dependant upon how many amps the relay pulled to operate. So with that being why does a relay require as much as 30 amps when its controlling circuits powered by 18 gauge wiring??????

I have a light switch relatively close by that has two prongs on the backside, both with orange wires attached to them. I checked at there are about 12-13VDC coming through. Are both orange wires hot or which one would I tie into? What precautions should I take to disengage power to the the 12VDC system, so I don't get shocked? Thanks again.

Sully2 wrote:

Executive wrote:
Make sure you use 10AWG wire for the relay....Dennis

Are you kidding? 10 ga will carry 30 amps. This gentleman is talking THREE AMPS

Read it again, Sully.....wiring for the RELAY must be 10AWG. For the SWITCH it can be 18AWG.....:W....Dennis

If you're going to be running a new wire anyway, the best thing to do is run it from your 12V distribution panel - where all your 12V fuses are. Or you can go directly to your battery bank - I would choose whichever source is closest to your switch, and/or easiest to access.

You're right, Allan. I only need to add 12VDC to the center post of the switch. My issue is finding a 12VDC source. I have a 110 outlet right next to the switch, but that won't work as I understand it. I also have 12VDC going to the heat register under the bath cabinet, but that current is controlled by the thermostat, so that won't work.

The coil side of a relay really doesn't care...
You can power either terminal and ground either terminal, and as long as the twain don't meet it will work...

you have 4 terminals...
coil 1
coil 2
input
output

The input is the high power for your load.

output is the load.
Coil needs ground on one side and power on the other to energize the relay.

A popular way to wire them is to connect INPUT and 1 coil TOGETHER and connect that to high power.

Then, to energize the relay, you just GROUND the other coil wire.

Sometimes, they spec one side of the coil is grounded. If so, you need to supply low current power to the other side of the coil. If in your main control panel, you can grab this from the tank sensors, or the water pump switch.

I think everybody is making a mountain out of a molehill here. Basically, all the wiring is already in place from the switch to the relay. The only change that is needed is the wiring at the switch itself: the center terminal on the switch needs to be changed from ground to +12V.

Simply find a convenient +12V line close to the switch location and tie in to it, using the appropriate fuse as recommended by the manufacturer. Depending on the location of the switch you might be able to run a line directly to your +12V distribution panel, or even right to the battery bank. No changes need to be made to any other wires.