Can anyone help me with a wiring diagram please?

[jMz]

Thanks for looking, I need to know how to wire in a second battery in the boot of my Sei. I know how to practically do it, but struggling with how it would be wired. Basically, I'll tell you what I need and hopefully you'll be able to tell me how to wire it together!
when the car is running I want it to charge both batteries,
only want it to use the main battery for starting,
radio to run from battery in boot when car is off,
with a switch.

I hope someone can do me a small diagram please, this seems so simple but it's got me baffled.

 

[Dcthebear]

Far easier to buy a high capacity battery that holds a bigger charge. What conditions (duration of time and volume) are you using the radio under out of interest?

 

[Eklipze3k]

http://www.split-charge-relays.co.uk/charging-systems/split-charging-relay-faq.html

 

[jMz]

The radio is on a permanent live so when I leave the car for a long period of time it just drains the battery. My options were to wire a switch on the radio so I can manually turn it on and off as required. At the minute I've just took it out of the car completely. I only really do short runs here and there so I can't be bothered plugging in the radio everytime I get in the car. It's no problem when I'm using the car normally, but sometimes it won't get touched for a day or two and that's when it's a pain in the bum. Also, when we go on long journeys I have a DVD player for the bairn in the back, and I just want to be sure it's not draining the main battery too much.
I'm done spending money on the car for a few months now so any solution will need to be free/very cheap.

Good shout on the Split Charge Relays, sounds perfect for what I need, but like I said I'm a bit strapped, I've got a bunch of wires and switches in the shed so looking for a quick homemade solution for now.

 

[EvoStevo]

Change the wiring for the radio so it is powered by a switched live instead.

 

[jMz]

Change the wiring for the radio so it is powered by a switched live instead.

If I knew how to I'd have already done that! Not sure which wire is which.

 

[volxstu]

The split charge relay is a switch. It when its in off position it breaks the circuit from front and rear battery. You cant just put an rocker switch inline to a 4 gauge piece of cable, itl just burn out.

For a Split charge you will need an inline fuse at the front battery and one within 30cm of the rear battery. At least 4 gauge cable going through the car and upgraded earth cables for the front battery. A switch to tell the Relay to power up or take a feed from the alternator charging feed.

Its not something that you should really be doing though if you cant figure out how to get a switched feed to your stereo.
Remember messing with car electronics is Dangerous if you dont know what your doing.

 

[jMz]

Yeah I've binned the idea of a second battery now, just looking to put a switch on the radio or to rewire it so it only comes on with the ignition. Still not sure which wires and what to do with them though.....

 

[volxstu]

Normally the fag lighter is ignition fed. Just tap a wire into that with an inline fuse.

 

[jMz]

Normally the fag lighter is ignition fed. Just tap a wire into that with an inline fuse.

Nice one. So I just plug that into the power on the radio and insulate the permanent live wire?

 

[volxstu]

You need to strip a a piece of the insulation away and then solder your perm live wire to it. Insulate it with some heat shrink.

 

[jMz]

Ok so apologies for possibly being stupid, but you are saying that I need to connect the cig lighter (IGN) to the permanent live going in to the radio? Will that not make the cig lighter permanent live?

 

[Eklipze3k]

No, you cut the permanent live cable going into the radio and replace it with the ignition live from the cigar lighter. The wire providing a constant live signal from the battery will then no longer be connected to anything.

 

[jMz]

No, you cut the permanent live cable going into the radio and replace it with the ignition live from the cigar lighter. The wire providing a constant live signal from the battery will then no longer be connected to anything.

Understood, thanks buddy. Job for this afternoon.

 

[volxstu]

Nope your not being stupid. I was tired last night. Ive just read what i told you to do
Your permanent live is fine as it is on the Head unit as the standard wiring for fiats is permanent only. You need to put the wire from the Fag lighter to the switched live. This will tell it to switch on an off with the Ignition.

 

[wilko1992]

Look in the guides and find the 1 I made for my punto, its the same for Sei as well and its dead easy to do

 

[kimi1984]

The radio is on a permanent live so when I leave the car for a long period of time it just drains the battery. My options were to wire a switch on the radio so I can manually turn it on and off as required. At the minute I've just took it out of the car completely. I only really do short runs here and there so I can't be bothered plugging in the radio everytime I get in the car. It's no problem when I'm using the car normally, but sometimes it won't get touched for a day or two and that's when it's a pain in the bum. Also, when we go on long journeys I have a DVD player for the bairn in the back, and I just want to be sure it's not draining the main battery too much.
I'm done spending money on the car for a few months now so any solution will need to be free/very cheap.

Good shout on the Split Charge Relays, sounds perfect for what I need, but like I said I'm a bit strapped, I've got a bunch of wires and switches in the shed so looking for a quick homemade solution for now.

Am i right in thinking you can swap two wires over on the back of the ISO lead on the headunit, so it switches off when you kill the ignition? I vaguely remember having to do this on my Tipo, and more recently my Marea as it too was permenantly on and used to drain the battery, especially if you have an amplifier wired up too!

Is this how all fiat headunits are wired up?

 

[volxstu]

No. 99% of Fiats are Permanent live only.

 

[jMz]

I went out to do it the other day and looking at the info on the head unit itself and the ISO plug, rather than chopping wires I reckon I can just swap a few wires to make it work as it should, luckily it says where the memory, and ignition need to go. Should be just a case of popping the wires out of the plug and putting them back to match the unit. Only thing I'm not sure about is the wires colours, I believe the red and green is ignition and the thin blue is the memory? Thick red one is permanent live, but this won't need to be used, and the black is the earth. Gonna give it a go anyway! How hard can it be??!!!

 

[jMz]

How hard can it be? I'm having a nightmare trying to get these wires out of the ISO block. It's so simple what I need to do but I've tried a small screwdriver, a safety pin, and a small nail to try and prize them free but they just aren't budging. I've read a few things online saying how you just have to bend back a little lug and they "just slide out", If I find the guy who wrote that.... I've got a hole in my hand, and I am no further forward. I'm going to persevere for a little while as I have a free hour this morning. Well, that's now 40 minutes left.