Wiring in my new stereo this weekend...

[mfunsta]

Having read up on all the relevant posts, I've formulated a plan.
I just wanted to run it by you guys and gals to check that I'm not going to blow myself or my new stereo up, and it's going to operate as I want.

Original unit was an old cassette player. The existing wiring into a power ISO block had three connections, a thick red wire (presume permanent live) and thin red wire (presume switched live) joined together, a brown wire (presume earth) and a blue/grey (presume dimmer/lighting). There was also four speaker connections separately to the unit.

My plan is to construct a new ISO block for both the power side of things and the speakers.
The speaker, earth and dimmer/lighting connections are pretty straightforward.
On the power side of things I have run a separate fused lead from the second (leisure) battery, this I will be connecting up to the corresponding yellow (labelled as Batt. perm live) terminal on the new stereo.
I will then disconnect the existing two red power cables; make safe the thick red permanent live and connect up the thin red switched live to the corresponding red (labelled as Acc) terminal on the new stereo.

The idea being that if there is any power drain from the stereo it will be taken out on the second, not the main battery.

Considering the above, will the stereo still play without the key in the ignition or should I just wire both new red and yellow terminals to the new second battery power lead?

Battery leads will be disconnected as necessary and I'm crimping the cables direct to the ISO terminals.

Any comments welcomed.

[Titus A Duxass]

I would power the radio completey from the 2nd battery.
That way if you are parked up you are using the 2nd battery and not the starter battery.

Incidentally, my light blue wire is for the auto-aerial. Check your wiring diagrams.

[Oldiebut goodie]

On one I have just fitted to daughter's car (so had wiring to hand)
iso plug A
4 12v memory
5 12v auto antenna
7 12v power
8 earth

So that blue should be aerial power.

[mfunsta]

cheers for the responses..
..the existing blue/grey I'm pretty sure is to do with the illumination because it is piggycaked from the cigarette lighter illumination

granted the new blue from the head unit is for the electric aerial/swiched amp and I will not be using that...

My first plan was to power both the head unit Batt and Acc terminals from the 2nd battery, just wondered whether the same result can be had by using the existing switched live instead, so it is totally off when the keys aren't in, as long as I can still use it. May just try it anyway.

SO, the choice is:
'Stereo Acc and Batt both to permanent live from 2nd Battery' or 'Stereo Acc to existing switched live/Stereo Batt to permanent live from 2nd battery.'

[mfunsta]

think I mean piggybacked...
...whatever piggycaked means!

[Titus A Duxass]

If you want totally off when the key isn't in use the switched 12v to drive a relay between your 2nd battery and the radio.

[CovKid]

Crucial bit is your new stereowill have greater current demands than your old one. Usually theres two lives, one for the memory and one for the main power. Don't twist those together or you'll be plagued with flat battery probs after three days as many of us have found. The drain, even with the stereo apparently switched off, can be rapid otherwise. Just bear it in mind.

[Oldiebut goodie]

think I mean piggybacked...
...whatever piggycaked means!

Bacon sarnie?

[mfunsta]

so is it the Stereo Red Acc lead which drains all the power when off? i.e. this lead should not be permanently live but somehow switched.

If so, will the stereo work when the key is not in the ignition.

[mfunsta]

mmmmmm... Bacon sarnie.....

why do I suddenly fancy a bacon sandwich... damn..

butty van on way home, methinks

[J188]

The stereo I have fitted in my van does not switch of when the key is taken out, if i remember rightly the ignition doesn't have the right switching part on to turn the radio off, so its wired to constant live. However If I remove the fascia it doesn't seem to drain the battery...not gone flat on me yet anyhow. Wiring it to the leisure battery though will mean you can listen to it when you camped up with no worries too

Post from a while back with similar issues with the radio not switching off when ignition turned off might be worth a quick read if you haven't already done so.

https://club8090.co.uk/forum/viewtopic.p ... 6&start=15" onclick="window.open(this.href);return false;

[mfunsta]

Thanks for all the responses..... mission accomplished....

Tried wiring the new stereo switched live to the switched live in the van, but unit wouldn't fire up.

So now, the second battery supplies the new head unit ISO with the fused permanent live supply, then untilised the stereos bullet connectors between the acc/red and yellow/permanent to put in an illuminated isolation rocker switch, so I can isolate the main power drain when stood for long periods of time......... just got to find a hole saw to mount the switch now!!!