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Discussion Starter · #1 ·
I am splitting my remote lead more ways than I feel comfortable with.... I have a mess of wires all soldered together to one lead coming from the H/U and my common sense tells me that this isn't the right way to do it. More specifically, I'm using a 10ga wire from the H/U out to the trunk currently, soldered at various points to a handfull of tiny little strands that came with some ancient amp kit. I was wondering what way there is to properly send remote turn on signal to everything without over-extending...

I searched, and it seems that people are using a "relay" - I searched to find out what a relay is, and the answer I got was "a switch"

How does a switch send multiple remote lines out? Also, what sort of "relay" would I use, and how should I set it up? What gauge of wire should I run to it, and subsequently to all my devices? (amps, active crossover, dash-mount EQ, neon lights, etc)
 

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This is the kind of relay you need.
12V/12 VOLT 30/40A SPDT RELAY w/ SOCKET & WIRE HARNESS:eBay Motors (item 220382121985 end time Jul-19-09 16:01:18 PDT)

You can also find these at auto parts stores. Just tell them you need a standard "single pin double throw relay". When you get it it will have 5 wires. They are labled as follows 85,86,30,87a and 87.
This is how you wire it.
85 - ground
86 - amp turn on wire from head unit
30 - Constant twelve volt or accessory
87a - not used, you can remove it completely by pulling on it
87 - Goes to all the units you want to be turned on - just like before.
Standard SPDT relays can handle 30 to 40 amps which will be plenty if all these devices have been running off of a head unit remote turn on anyway. Make sure the ACC or Constant 12v wire you connect to 30 is able to put out high current, I would go to the ignition harness. Pretty easy. Or you could go to a install bay and I would be surprised if they charged more than $40 to do it.
Good luck!
 

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x2... i was just using a single butt connect before (2 processors and 3 amps) but bumped it to a relay since the voltage was getting low... 11.3v

i tapped the cig lighter output for power since it was right there and i was being lazy
 

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A relay is designed so a control voltage can activate a line voltage to energize as many devices as you want to [ without damaging the HU in this instance ];)

If the HU is damaged you can pull it and either buy a new HU or send it in to be repaired :)
 

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use a relay - its the easiest and cheapest way - most electronic stores will be able to give you 12v automotive relays for cheap - and its easy to get a diagram as to how to make it work

more info on relays

Relays

what you will be using is referred to as a bosch relay on there
 

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The general rule of thumb is two amps are considered safe, but if your going to run more than that or fans as well you'd be better off using a relay.
 

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Wow, first install coming up and I hadn't even considered this. I'm confused by the Bosch relay diagram, I could only get 1 of the lightbulbs to throw light at a time. But I need voltage to both amps... what am I missing here.
 

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I'd recomend this relay socket. The diode will protect your HU incase you get any back current from the relay. I got one a while ago and if IIRC you'll have to switch one of the wires. It'll take about 10 seconds. Parts-Express.com:12 VDC 5-Pin Relay Socket w/Diode | socket relays relay socket relay pins pin diodes diode DC bosch relay 12v mayhem
That would work, but you need to cut the red loop and move the white wire to the blank spot. Hook everything else up like I said in the first post. I really dont think the diode is necessary,but if you want to be extra safe.
 

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I'm not a fan of the bosch style relays for this application. The coil on some will pull upwards of 200ma which may be more than several amps combined. Some amps will require only 1ma to turn on while others may require 50ma or more. First thing I would do is get out your dmm and see how much current is being used without a relay before you decide if you really need one or not. If you insist on using a relay I'd try to find a smaller one that has a lower current requirement for the coil or if you insist on using a bosch style relay I'd use the circuit about halfway down this page to lower the required current for the coil.
Basic car audio electronics.
 

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Discussion Starter · #17 ·
This won't be a problem at all. My dad is a mechanic, specializes in automotive electrical systems - if I ask him for some help he'll probably give me the relay for free and show me how to install it.
 

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CLEAR! Bringing this one back from the dead.
I'm going to add idq-31's to my setup and I bought a relay. But I'm not sure it's going to be better than just daisy chaining my remote wires which is what I did when I just ran the two jl amps in my sig. I was reading that the relay could draw more than everything else. This is the relay I got off ebay. It says it's a horn relay though? All the terminals are numbered the same as the diagrams on bcae1.com so i'm just not sure.

Automotive Electrical, Horn Relays | TESSCO 800 472 7373
 
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