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Car stereo wiring q...
 

[Closed] Car stereo wiring question

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[#8413347]

Because if you have a car problem STW seems to be the place to go these days!

I have a mid 80's car on which the radio doesn't work. It worked when I test drove it but between then and picking it up the seller fitted a new relay to make the electric windows work and now the radio doesn't work. I have a suspicion it's the relay that's gone, but new relays for these are very expensive (£70) as they also go to the sunroof.

The sunroof was never going to work anyway so I was hoping to wire a new stereo in straight off the battery with an inline 10a fuse and ground it near the fusebox where everything else is grounded. The radio is not connected to the ignition so I can live with it being constant on, removing the face should prevent battery drain.

I wanted to know if the existing stereo used a relay, will I then need to wire in a new relay to make the speakers work, or will this all just go? If it needs another relay I'm not confident I could deal with the rat's nest behind my dash to find the speaker wires - stuff seems to go in all directions and into places I can't get to to trace them.

Thanks.


 
Posted : 23/03/2017 9:37 am
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You just need to get power to it. Everything else should just work. Earth can be any nearby bit of metal. Should be some power locally, maybe lighter socket, or as you suggest a new wire with fuse


 
Posted : 23/03/2017 9:42 am
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It would be worth the effort to find a constant live and an ignition live, keep all your settings and avoid power drain.

Also what car? Anything exciting?


 
Posted : 23/03/2017 9:44 am
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Just needs constant live through a fuse. To both the constant and switched live of radio. Usually red and yellow.

Face off is good disables main power and it will only be feeding to the constant live (IE the low drain keeps settings side of it)

This is how i have it set up in the landy.


 
Posted : 23/03/2017 9:51 am
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Nickjb- there is a lighter socket but I'm wary of fettling that as we're dependant on it for charging phones/cameras/gps etc on a tour of France and Germany we have planned.

So, in theory, the speakers are wired straight to the stereo and don't go through the relay?

Pictonroad - even the original stereo (which I've still got) didn't have an ignition live! I think so long as we're aware of it then it shouldn't be a problem.

Info on the car is here -

http://singletrackworld.com/forum/topic/new-bike-car

[img] [/img]


 
Posted : 23/03/2017 9:51 am
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I would echo the above about finding a switched live and perm live. If you're going to go to the hassle of running a wire from the engine bay then it may be worth doing another 10 minutes worth of fettling behind the dash to see if you can find a switched.


 
Posted : 23/03/2017 9:59 am
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I would also look around for an empty relay slot....Probably in fuse board

I suspect what Mr man has done is removed relay from the radio to the electric windows .

All the relay does is opens up the 12v live from the battery via applying an ignition switched live from when you turn the key to close the circuit direct from battery.


 
Posted : 23/03/2017 10:06 am
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I suspect what Mr man has done is removed relay from the radio to the electric windows .

+1. There will either be a gap where the radio relay was, or a broken electric relay where he's swapped them over.

Seventy quid, [s] relay [/s] really? Ebay / scrapyard / Maplin?


 
Posted : 23/03/2017 10:20 am
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It's not 70 quid for a relay.

Maybe for one with Porsche written on it.........

Meanwhile back on planet earth a relay will be about 10 quid.


 
Posted : 23/03/2017 10:25 am
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Relay not required.

The best plan is to get to the back of the ignition switch at the column and ID the permanent live (for the audio memory), ground and switched live. Make all you your connections there.

You must fit a fuse into the permanent live and maybe the switched live.

Heat shrink
Soldering iron
Insulation tape
Fuse holder
Fuse
Wire
Volt/power probe (or a bulb and a bit of wire).

Got that lot?


 
Posted : 23/03/2017 10:34 am
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I'd argue new wires not required if it worked before matey changed a relay to make the windows work.....


 
Posted : 23/03/2017 10:38 am
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if it's the same relay for the sunroof as the stereo, is it [url= https://www.ebay.co.uk/itm/322172983955 ]This one?[/url] if it's not then you'll find one for less than £70 I'm sure
I'd be inclined to fix it properly rather than bodging wires all over the place
You win most hideous wheels seen today award btw, though the poo brown colour actually polishes up quite nice..


 
Posted : 23/03/2017 10:39 am
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Genuinely £70 for the relay! They're famous for it, it's unusually specific. For whatever reason this relay doesn't live in the boards for the relays above the fusebox, it's loose on its own, completely separate from the other relays. There's no spare relay slots unfortunately.

Khani - nope, that's not it. There's only one on ebay that's £30 plus £50 postage from the US. Used ones seem to be about £30-35.

Marko - got all that.


 
Posted : 23/03/2017 10:45 am
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I'd get a used one then, nowt worse than an old nice (apart from the wheels) car that's had the electrics bodged about with,
If it's an S they're getting rare now so you want to keep it straight,
Those wheels make Jesus cry..


 
Posted : 23/03/2017 10:49 am
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It's not an S. It makes no pretence of being remotely rapid!

The wheels are stock, though. I like the wheels but hate the colour.


 
Posted : 23/03/2017 11:09 am
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I like the wheels but hate the colour.

The worlds upside down nowadays..


 
Posted : 23/03/2017 11:17 am
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Have you tested the sunroof relay to check it is indeed spackered ?

Remember #WWECD*

*WHAT WOULD EDD CHINA DO 🙂


 
Posted : 23/03/2017 11:40 am
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Dont know if this is any use to you,

The six-pin connector commonly used in mid-80s 924/944 has two large pins and four smaller ones:

Pin 1) Brown - Ground (large pin)
Pin 2) Red - 12v switched power input (large pin)
Pin 3) 12v illumination power input (from pin 4)
Pin 4) 12v radio-switched output (to pin 3)
Pin 5) 12v radio-switched output (to power antenna)
Pin 6) Permanent 12v input (to maintain memory)
A second set of power connectors are provided for the optional equalizer/amplifier:

Brown - Ground
Red/white - Permanent 12v power
Red/black - 12v when radio is switched on.

Might be worth trying a multimeter on the connections,
also a quick google suggests that the ignition switch can be the culprit with non functioning radio on 924's(besides the relay)


 
Posted : 23/03/2017 3:32 pm