How do most people wire up all the 12v constant feeds. Lets say between various harnesses an accessories you have a total of 6 12v constant requirements. How do you keep that looking clean instead of 6 lots of home runs back to battery. Some sort of BUS/common bar ? thx
It depends what the loads are, where they're located, etc. A large wire and a bus bar might do the trick, if the loads are kind of high and the feed wires all need to be in the same place.
Running them off the battery is messy. you can run a wire of constant power off your starter motor lug Up to : A terminal strip Small fuse box Do like the oems and have splices in the harness off one wire and send the other 5 runs where they. Need to go. I like fuse boxes and terminal strips as if there is an issue it’s easy to isolate the problem circuit. just stacking 3-4-5-6 wires on a battery terminal looks like crap
you may need to enlarge it, but on the firewall below the water heater hoses are two wiring blocks. Inside is the ground block and outside is the hot block, further outside and a bit lower are relays. Most of the wires coming off the hot block have fusible links. It is not all pretty, but is reliable. It is an 8 or 10 coming from the battery.
I never source off the battery, too much acid. Like said sourcing off the constant power lug on the starter solenoid/ relay. I also try to keep these at a minimum, using “ buss bars” terminals, etc. I try to route the wires somewhat together , keeping the wires just long enough to reach. I always crimp,solder, and heat shrink. Then tie the wires to “ things” with stays. I try to keep them in straight lines, for appearances. Just some of the things I do in wiring. Bones
Still thinking of where to hide my relay board ......... looks a bit like .... Right now its just the 12v MAIN power on wires to battery _and this). Eg Main body harness 21 circuit. Fuel injection harness Other accessories.
Something like this right ? https://amzn.to/2MoxPdj Then just route that somewhere under the dash for example ..... and wire all 12v constant to it, as long as the rest of the wire circuit is fused.
Why relay every circuit? Usually you just relay high amp circuits and switch normal circuits. This thing is adding a lot of unnecessary wires and circuits for a race car. In my opinion. You have to have power go to the switch, back to the relay, the relay has to grab power and make ground and send to load. Why not just switch load? Bones
Go to an electronics store and buy an accessory fuse box (about $10), run a large hot wire to it, then to all your hots. That way you keep a clean look and have fused protection too.
I will just be doing switch load for the harness/regular draw accessories. That relay setup is really for my AC and FANS and /or any other high draw independent accessory,
Thanks. Leads to another question .... Using the EZ wiring 21 circuit harness. At end these are all teh fused circuits. Wiper - 15 Amps Radio - 10 Amps Stop - 20 Amps Turn Signal - 15 Amps Radio - 10 Amps Fuel Pump- 15 Amps Coil - 30 Amps Gauges - 10 Amps Dome - 10 Amps Hazzard - 15 Amps Horn - 20 Amps PWR Window - 20 Amps Headlight Breaker A/C Heat -30 Amps ; Door Lock - 20 Amps Blect Fan - 20 Amps Cig Lighter - 20 Amps Backup/Cruise - 10 Amps I know typically you wouldnt have ALL circuits on ... but you could in theory have a lot of them on which would be close to 200AMPS. Not sure real life draw ..... just rated amps for circuit. But the entire harness is powered of a 10Gauge wire from starter. Wire must be over 6ft long as a guess to then go into fuse block inside car ..... - according to this chart can only handle around 50-60 Amps. http://www.offroaders.com/technical/12-volt-wiring-tech-gauge-to-amps/ So what am I not understanding thanks
Every harness I've ever seen has used either a 50 amp or 60 amp main fuse and I've never seen one pop except in the event of a direct short to ground of the main wire so I doubt you will ever load up enough to overload it. Plus, keep in mind those numbers are the max the circuit can handle without popping the fuse- not how much the circuit handles regularly
Picture is sanitary, and the way i'll wire. Just not as many relays though. FP relay will be close to pump in rear, headlights, horn, fan will be towards the front. Have to split them up, and not run extra wire when unnecessary. But- That pic is a clean install IMO. As long as it's clean, and correct=loads/draw, it's an open interpretation of how it's configured.
This^^^^^^^^^^ Will be an issue............ I'de up the gauge quite a bit myself. A ten wouldn't suffice just from an alternator to a bat(+) lug=be it battery,or starter +. I'de call an 8 iffy depending on load........ a 4 might look a lil overkill, but with the /your demand at full boogie, it should save your bacon. Wires don't play real nice/electricity when things get a lil warm,or hot.
The fuse for each circuit will be sized to protect the wire for that circuit. Hopefully the wire for each circuit, is large enough to handle the current drawn by that circuit. The total current that the feed needs to be able to support, depends on how many "things" are running at once, and how much current each one actually draws. Just adding up the fuse sizes won't get you a very accurate measure of this!
Yeah I did some googling of amp draw on stuff I will run. Lights. Ac switch. Radio. Electric rear brake switch. Turn signals. Gauges Probably all under 20A real draw. So should be good. Fuel pump and fans on standalone relay circuit.
All vehicles have three busses. Battery, ignition, and accessories. A good fuse panel will have these busses identified and be easy to wire. I have used a Centek panel many times. The battery feed goes from the starter solenoid/relay to the ignition switch. From there the battery wire goes to the battery buss on the fuse panel. The ignition wire then goes to the ignition buss and the accessory wire, to the accesory buss. Each circuit on each buss should be fused at the buss and then run to the system being connected. The heavy #10 at least from the alternator can run to either the ignition switch battery terminal or as I prefer, to the battery buss terminal with the lead from the ignition switch. That's basically the power distribution of any automotive electrical system, no matter the manufacturer or wiring installer. Just remember that every load must have circuit protection either by fuse, circuit breaker, or fusible link. I remember one time I was modifying a factory fuse block for Model A I was wiring for a friend. Another mutual friend stopped by and asked me what I was doing. He said you don't need fuses if you wire the car right. I didn't put one fuse in my entire car and it works perfectly. I looked at him and said good luck. It wasn't a year later that one of his wire bundle supports broke loose allowing the harness to chafe and short out. Poof! Smoked harness and interior before they could disconnect the battery. Circuit protection is parimount! Hope this helps.
I put a terminal strip on the frame forward of firewall on passenger side. 37 fenders keep it out of view. Two heavy wires from starter to strip. Five terminals are strapped together. From here: - one fusible link for fan - one fusible link for stereo amp - one fusible link for siren (I'm a police car) - one fusible link for wire to B terminal on ignition switch. Ignition switch terminals A and I wire to nearby fuse panel under dash. Everything else wires from fuse panel via harness. Hope this helps
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