Enthusiast III
Proper 12V Auxiliary LED Wiring How To!
- Thread starter Granite Ridge Overland
- Start date
Enthusiast III
Good info here, thank you.
I have a question about hooking up the auxiliary fuse/relay panel.
If I do a basic connection from the aux fuse block to the battery then all the circuits will be hot all the time, correct? If I want the aux panel to only be hot once the key is in and the ignition at or past ACC then I would have to hook the main positive some where else...but where?
Or is doing that even feasible?
Thanks for any advice.
I have a question about hooking up the auxiliary fuse/relay panel.
If I do a basic connection from the aux fuse block to the battery then all the circuits will be hot all the time, correct? If I want the aux panel to only be hot once the key is in and the ignition at or past ACC then I would have to hook the main positive some where else...but where?
Or is doing that even feasible?
Thanks for any advice.
If you want your aux panel to only be powered when the key is on you can use a relay to switch your aux panel on and off and control the relay using a +12v signal switched by the key.
1. Put your main fuse as close to the + battery terminal as possible.
2. Connect the other side of the fuse to pin 30 on a relay.
3. Connect pin 87 of the relay to your aux panel.
The main fuse and relay need to both be sized large enough to support your intended loads. Then you can pick a wire gauge that can support the maximum current, determined by the fuse size. For example, if you anticipate a max 40A of loads connected to the aux panel your fuse would need to be larger than that (say 50A) and your relay would need to be able to support at least whatever the fuse is rated for. You can then use a chart like this one to look up the proper wire size (AWG) for the max current and wire length.
The last step is to use a low current switched signal to drive the relay. This will likely be the tricky part. One option would be to tap into the accessory circuit (cigarette lighter) either in the car or at the fuse block under the hood. In most vehicles this is switched +12v, and you would hook it to pin 86 on the relay and then ground pin 85.
The numbering system for relays is a bit confusing, but the important thing to keep in mind is that pins 85 and 86 power an electromagnet that when energized activates a switch that connects pins 30 and 87.
1. Put your main fuse as close to the + battery terminal as possible.
2. Connect the other side of the fuse to pin 30 on a relay.
3. Connect pin 87 of the relay to your aux panel.
The main fuse and relay need to both be sized large enough to support your intended loads. Then you can pick a wire gauge that can support the maximum current, determined by the fuse size. For example, if you anticipate a max 40A of loads connected to the aux panel your fuse would need to be larger than that (say 50A) and your relay would need to be able to support at least whatever the fuse is rated for. You can then use a chart like this one to look up the proper wire size (AWG) for the max current and wire length.
The last step is to use a low current switched signal to drive the relay. This will likely be the tricky part. One option would be to tap into the accessory circuit (cigarette lighter) either in the car or at the fuse block under the hood. In most vehicles this is switched +12v, and you would hook it to pin 86 on the relay and then ground pin 85.
The numbering system for relays is a bit confusing, but the important thing to keep in mind is that pins 85 and 86 power an electromagnet that when energized activates a switch that connects pins 30 and 87.
Enthusiast III
Thank you, after looking at some info about relays and your explanation I think I get it now. I’ll need a relay, an anl fuse and one of those add a circuit things.
I can see this working now. Thanks again.
How did you wire the yellow and white wires to the switchpanel?
Ideally, I would like it on the dimmest backlight to come one with headlights and the red 12v to switched power.
But no one seems to know how to wire the yellow and white wires?
Ideally, I would like it on the dimmest backlight to come one with headlights and the red 12v to switched power.
But no one seems to know how to wire the yellow and white wires?
Enthusiast III
What is 87a on a five pin relay for?
I’ll assume I’d want a four pin relay in any case.
Or can I use the five pin and just pull that wire out, not use it?
thanks again for answering my dumb questions
I’ll assume I’d want a four pin relay in any case.
Or can I use the five pin and just pull that wire out, not use it?
thanks again for answering my dumb questions
Member III
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- First Name
- Jim
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- covey sr
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16986
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I'm happy with the info too. I've been looking at that gland on Amazon for six months while trying to figure a way to enter my rig with my solar wires and not look amateurish. Also I want a way to get into the rig with my rack lighting wires without monkey rigging it through the A or B pillar posts. That grand is an answer to both wiring fixes. I plan to connect them to a panel inside the rig to power up everything I plan to hook up.
Awhile back @007 posted some pictures of his rig wiring and it was great. We need him to come back and show us again.
Member III
- 2,827
- First Name
- Jim
- Last Name
- covey sr
- Member #
-
16986
- Ham/GMRS Callsign
- none - BREAKER BREAKER HAND HELD CB AND WALKIE TALKIE
When I see you I will want to talk to you about this and a lot about radios ect. :-)
I've ordered a very similar fitting off Amazon for the same purpose. How did yours turn out? Any tips?
Advocate III
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- Michael
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- Rose
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20990
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It was a lot taller than I expected... as for tips... hot soldering iron... and take your time... make your harness about 2’ longer than you think you need and start feeding the harness from the roof to where ever your relay panel is... for the light side of the harness, again lay the wires from the lights to the harness and give yourself about 2’ of extra wire. Wire the lights in place then solder the bulkhead fitting last trimming the wires to length at the connector... lastly don’t use silicone to seal the connector to the roof as this will induce leaks with the supplied rubber gasket.
Advocate III
- 5,584
- First Name
- Michael
- Last Name
- Rose
- Member #
-
20990
- Ham/GMRS Callsign
- W7FSB
- Service Branch
- US ARMY Retired
I’m all ears Jim... wiring is my second favorite thing to do... first favorite is playing with radios.
Enthusiast III
Another big thanks for the help. I’ve got my aux fuse box wired in through a circuit breaker and a 60a relay and it’s working just as desired. I just didn’t like the idea of having it powered at all times and this shuts it off once the key is turned off.
