wtf have i done

i have been putting a stereo in the 90 all was well i had the 4 speakers going but couldnt find a earth for the 1 . so when i started the landy i would have no sound so i earted the speaker to the stereos main earth stupidly. went to strart her turned the key and bang i lose all my elecrics . it all worked fine till i went to start her . disconnected the stereo but still no electrics have i blown a relay probably something simple but i run out of light never had no problems with any of me other wiring jobs in the old girl:doh:

why were you earthing the speakers?

they work on + and - polaritys...

not any more, it dont.

The Mad Hat Man said:

not any more, it dont.

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so why do you get cables marked with - and +..if ya get em round the wrong way the speaker works incorrectly

coz its all to do with phasing, Series38.
if yu play a sound through 2 speakers with opposite phase, it cancels out the sound of each other., thats how exhaust sound deadening systems work.

how do you know this stuff MHM?

bevhelee said:

how do you know this stuff MHM?

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google

Speakers don't usualy have an earth - they have a +ve and -ve and they usualy 'float' the AC not tied down to an earth - helps reduce interference. Some car units do earth the -ve so connecting the -ve to the body should work - this will be the case if you don't have a +ve and -ve for each speaker. - I would check your wiring. The radio unit will obviously have an earth.

As for the loss of the electrics - have you checked the fuses????????

What model landy do you have?????

As for where I know all this from, being a sound enginear helps a bit

speakers have a negative and positive dont they the stereo is ripped out another car thats all its a 90 mate

bevhelee said:

how do you know this stuff MHM?

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Coz i am a member of the Instute of Acoustic Engineers?

long story - suffice it to say I aint Daft .

If you want to know more about phase linking in audio equipment - try googling "Haffler" - one of the original "Surround Sound" systems - whereby in a stereo system - two rear mounted speakers where connected out of phase across the positive side of the two main speakers (try it) the two rear speakers play the difference between the left and right channels, but out of phase - so a signal passing from the left channel to the right channel appears to go from the left speaker, behind you, across and back to the right speaker - awesome!

The Mad Hat Man said:

If you want to know more about phase linking in audio equipment - try googling "Haffler" - one of the original "Surround Sound" systems - whereby in a stereo system - two rear mounted speakers where connected out of phase across the positive side of the two main speakers (try it) the two rear speakers play the difference between the left and right channels, but out of phase - so a signal passing from the left channel to the right channel appears to go from the left speaker, behind you, across and back to the right speaker - awesome!

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but the original qs wasnt about phasing

I didnt say it was - but + and - are references, not absolute - it dont mean 12Volts and earth, but you have to connect the two +'s to the correct terminals and the two -'s to the correct terminals on the radio, those signals arent anything to do with power at all - just to do with the audio signal.
If you dont believe me, take one of a two speaker system and wire it - to + and leave the other wired correctly - the volume will be significantly reduced, purely beacuse one speaker is trying to cancel out the other.

What the OP has done is to short the power output to the speaker to earth, thereby blowing any output transistors and fusing half his fusebox, by the sound of it .
I was trying to explain why speaker wires have a "+" and a "-" on them.

thats true,but the way you replied to the answers it seemed as tho you were saying speakers didnt need + and -.as i said in reply one he should have never wired the negative side of the speaker to the vehicles earth

my bad - i was trying to explain why they have that marking on them - its nothing to do with power. Maybe i explained in a bit too much detail .

so like i said in reply 1..dont connect the speakers to the vehicles negative side
getting back to his qs yes youve prob blown some fuses somewhere.hopefully just on the power supply to the stereo

wiltshire landyman said:

so why do you get cables marked with - and +..if ya get em round the wrong way the speaker works incorrectly

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You sure you never sent a live up the speakers, or you have the earth and live connections the wrong way for the hi fi, big bangs aint normal for speakers earthed, or shorted only tiny amps

Aint an old 90 with possy earth or sumat, but sure as fook you sent a big spike into the hi fi. Fuses first port of call and disconnect the hi fi until you understand electrics.

Just a thought. If he has a crap normal earth, (Common for old Land Rovers) then could a well earthed radio become the earth for the starter? That's a lot of amps for a radio to take and not the good kind. Would explain a few things.

but why only after he "earted the speaker to the stereos main earth"

The Mad Hat Man said:

but why only after he "earted the speaker to the stereos main earth"

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There is some info missing somewhere.
Why would it take out all his electrics on only start up?

It was just a theory, and posted as such.