Powering UHF and 2x Dual usbs

Hi Guys,

Looking at powering UHF and and a couple of dual usb rockers that im gonna put around handbrake area and have a couple of options. Really want it wired to accessories so that I know there gonna turn off as don't have a proper dual battery setup at present. Was thinking
1) splice uhf off stereo accessories wire and usbs off the cig lighter
2) UHF and usbs off stereo accessories (not sure if this is too much draw)
3) UHF and usbs off cigar lighter accessories (again, not sure if this is too much draw)

Read G-Dubya`s thread on installing and he went off aux battery, would prefer not too. Wondering if I need a fuse box if using options 2 and 3.

Any help or advice is greatly appreciated guys. Cheers.

Easy way is one of these.http://www.narva.com.au/products/browse/add-a-circuit
Just use the cig circuit, it will have ample ability to power everything.

Hi Christos. In my thread I used a relay that was switched on via power from the cig lighter therefore, the power to the USB's etc. doesn't add onto the cig lighter circuit. When there is no power to the cig lighter, the relay cuts power to the USB's so there is no chance of the battery getting flat. In my D22 I have 2 starter batteries in the front of the car and an AUX in the tub. The USB's are run off power from the front batteries.

Also I used a fuse block to separate the power supplied by the relay to the accessories I was running. Always use a fuse on any connection coming from a battery. For the small amount they cost they can save a lot of $$$$ if there is a fault and something shorts and catches fire.

Hi G-Dubya and John,
I will be honest, I started getting a little confused at the relay and waeco adapter part.... as I understand nothing about relays. Have been looking at fuse blocks and will definitely add one into the circuit. Have started to learn about relays today so hopefully I can use it in the circuit.
Still quite confused about it though to be honest.
Those look quite simple to use John, will this always be fused "on" if it is plugged into the fuse socket in the panel and drain from the battery?
Thanks guys for the replies.

That add a fuse will only supply power from a circuit when it is active. The cigarette lighter fuse will only be active when the ignition is in the acc or on position, so it won't be on with the key removed. Personally, I wired my UHF and usbs off the acc feed from the ignition barrel under the dash. I have a USB port in each of those switch blanks on the bottom of the instrument cluster surround...

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The cig circuit is good for around 120watts so it should power just about anything as long as you don't light a fag. You wouldn't tap into the blower circuit for instance.

A relay has numbers allocated to each pin, usually as follows:
30 - Power In, power from the battery
85 - Earth, connected to chassis or battery
86 - Switch, connected to the wire used to swith the relay on (eg cig power, acc wire)
87 - Power Out, will supply power when swith is activated
87a - Will supply power when 87 is not active. I covered mine with an insulated spade connector.

The numbers above are for a 5 pin relay. A 4 pin relay won't have an 87a and will not supply power unless switch is active.

Thanks heaps for the info everyone,

Thanks so much for that explanation on the relay G-Dubya, makes it pretty clear (getting my head around it now)

So the plan is to use add a circuit to tap into the fuse box to run the uhf and 2x dual usbs.

Am I correct in saying I can then run the add a circuit from the fuse box to a relay and then to a fuse block to separate everything to individual fuses from there without dramas?

Is it possible to use a add circuit line to a battery fuse (ie, room light) for no 30 on the relay so I don’t have to feed it all the way to the battery?

I have had a look at my fuse box and have a few empty spaces that don’t have anything in them (ie, 20A headlamp cleaner WTF is that), can I use these instead of cig lighter and what amp fuse should I put in them?

Last question, are they mini or micro fuses in the 2014 D22?

Really appreciate the help guys. Chris

They are mini fuses. You may be able to use one of those empty fuse slots for the add a fuse, but it depends if the power supply is wired to the fuse box. You need either a multimeter or test light to check and see if there is power to it.

If you are going to add your own separate fuse box and wire a relay to run it, it will only be active when the key is on. If you are going to go this way, it may be worth getting a 60a relay and wiring to handle that current, plus a circuit breaker to put near the battery on the feed to the relay. That way you could get a fuse box with a common positive feed and run quite a few different things off it. With the 60a relay, you won't have any hassles running a few different things from the fuse box.

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Hi Guys,

Apologies for the late reply, have been trying to plan this out with the accessories and such.
I have been doing a lot of reading around the forums and most people recommend connecting the uhf directly to the battery (initially was gonna run it off cig lighter, people have gotten me paranoid about not having keys and other safety reasons so maybe connect it to battery….aarrrggghhh, decisions. Lol )

Great news though… have tested all the empty fuse sockets with a multimeter and they all have power when in the correct states eg. batt, accessories and ign 1 and 2. Winner, winner chicken dinner.

So I have 1x 20amp accessories socket (head lamp cleaner) that I will definitely be getting use of.

Also I am removing the cig lighter itself and replacing it with a dual usb 4.8amp (2x2.4 amp, which by my calculations I still have 10.2 amp on that fuse circuit to use)
The new stereo I have picked up to install has an additional power requirement of a constant 12v power which needs to be hooked up to the 12v battery and has a 15 amp fuse (this has thrown me into a bit of turmoil as I am now gonna have to run a cable to one of the battery in the eng bay). Plus side is I can run the UHF off that connection if needed or I noticed that the interior light is on a 10 amp circuit from the battery I was thinking of just taping into that with an add a circuit.

Decision, decisions…..so fun yet frustrating at the same time.

Cheers for the help so far guys

+1 for what bods said regarding the relay. The higher the amp rating of the relay the more current you can run through it without having problems. You should work out what your max current draw will be and make sure you get a relay big enough to handle it. Make sure any power supply cable taken from your battery is fused with the fuse as close to the battery as you can get it to reduce the possibility of anything melting or catching alight. Lastly adopt a kiss method (keep it simple) as when something is more complex it can be more difficult to fix if you have an issue out on the tracks. I hope it all works out for you.

I probably wouldn't use the add a fuse as your power source for your relay either. If your add a fuse is only rated at 10 amps and you need to use 30 amps to power all your equipment the 10 amp fuse will continually blow. It could also affect the circuit you are tapping into as well (e.g. Power cable to that fuse may only be rated to 15 amps and the extra draw could damage it and cause a short). 6mm or 8mm twin core would be the smallest gauge I would use to supply power to a relay for the types of things you are wanting to run and the longer the distance of the cable you use the thicker the cable needs to be. The switch source doesn't need to be rated that high as it is only activating the switch. The add a fuse could be used to activate the relay (86 numbered connection) without an issue. Just make sure the fuse is rated less than the rating of the wire so it will blow before the wire melts. Hope this doesn't confuse you any further.