fitting a CD player

Post by **Idral** » Fri Nov 19, 2004 6:16 pm

I tried to fit my CD player today, I thought it couldnt really be that hard, I know a bit about electronics and 'thought I' had a rough idea what to do.
I cut off the adaptors and because I didnt want to take it to the fuse block I twisted the live and fuse block wires together (red and yellow). I then took this wire to the live terminal of the battery and took the black wire to next to the earthed terminal of the battery.
all seemed to be going well until I connected the CD player for the big turn on, 'pop' the 15A fuse went on the back of it!
Anyone got any ideas why??????? All I can think so far is that I did not have an inline fuse connected and/or that it was because I did not have and speakers connected. Also I am sure that the battery is the right way around.
Please help!

Post by **aupickup** » Fri Nov 19, 2004 6:43 pm

have you checked your cars polarity, negative or positive.

if fitting a modern cd player then you need your car to be negative earth

Post by **Idral** » Fri Nov 19, 2004 7:20 pm

100% sure the negative terminal is earthed

Post by **MrA.Series** » Sat Nov 20, 2004 2:22 pm

Yes, but is the metal case of the CD player touching the metal of your dash/shell/etc...
If so your car may not be negative earthed and your's just shorting the whole car battry through your CD players case.

Easy way to check polarity, which battery terminal does the braided strap connected to the body go to? IOf it's the (+ve) one, your car's positive earthed, if it's the (-ve) one, it's negative earthed.

Post by **edd** » Sat Nov 20, 2004 3:10 pm

100% sure the negative terminal is earthed

u would assume that means the battery

Post by **bigginger** » Sat Nov 20, 2004 3:46 pm

I remember having problems with the red/yellow wires when I fitted mine, it said the yellow was for an "accessory switch" or something. Can't remember what I did with the yellow wire - and it's raining, have just been out to the car to check but it's too wet to stay outside and take the CD out to find out, it's a bit of a job. Have you tried simply not connecting the yellow? If it ever stops raining, I'll have a look, promise.

Post by **Idral** » Sun Nov 21, 2004 10:57 am

It is the negative terminal that is earthed, 100%.
The battery is about 1 month old and it was the blue wire for accessorys which i have just put a knot in and left alone. The case was not in contact with and metal at all.
Could it be because I earthed at the terminal and not on the shell of the car, possibly this adds resistance to the circuit?
Also there are no speakers connected yet, could this cause a problem?

Thanks

Post by **edd** » Sun Nov 21, 2004 1:52 pm

Speakers shouldnt be a problem UNLESS the wires were able to short out. Byt the shound of it the 15 amp fuse isnt inline with the input pwer but on an aditional circuit as a standard cd/radio 4 x 25w should only draw between 2 to 3 amps (mine draws 1.5 but only using 2 speakers)

i would double check wires are not shorting (though i asume you did)

Edd

Post by **bigginger** » Sun Nov 21, 2004 2:42 pm

I had a look and have PM'ed you, not helpful, exactly as you have done except earthed through the body. Sorry.

Post by **bigginger** » Mon Nov 22, 2004 3:46 pm

Idral, how did you get on? Any lucK?

Post by **Alec** » Mon Nov 22, 2004 3:56 pm

Hello Idral,
just read this thread, although modern amplifiers are protected it is bad practice to switch on an amplifier with no load on it, i.e. the speaker or whatever device it drives disconnected, the amplifier goes flat out trying to see some current. Try connecting the speakers.

Alec

Post by **MrA.Series** » Tue Nov 23, 2004 10:15 am

I agree.

Post by **bigginger** » Tue Nov 23, 2004 11:48 am

But from experience, you're incredibly unlikely to damage a small solid state amp by so doing. Don't try it with a valve amp though, unless you like the smell of simmering transformer - at least I think that's what the smell was. When it happened to a friend, obviously..

Post by **Mrmog** » Fri Jan 21, 2005 10:01 pm

Hi this wil not help just to make you pixx your self I once wired up a mates mk 2 escort .And as he truned up the base the brake lights flashed too the beat.But then it was a ford .And I tuck the wire off the fag lighter.?
steve