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Discussion Starter #1
Hi all,

Recently bought a used 2003 156 (revised dash with the factory Bose system). I am having trouble with the sound cutting on & off at random. The Blaupunkt H/U seems OK as the time ticks over on the CD. Strongly suspect there is an issue with the connector on the amp side (wiggling the cable there results in it cutting on/off also). Anybody else had this problem? Any solutions?

BTW - Alfa South Africa are pretty useless.

Thanks in advance.
 

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AO Silver Member, 155 Lounge Winner 09
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7,713 Posts
uncommon problem i suspect.

do you know the history of the car? perhaps the previous owner had temporarly removed the amp in favour of a bigger, better stereo. as a result, reconnecting the factory amp has created a bad connection.

the solution would be confirming if it's simply the plug that's poorly connected, or if there's a broken wire at that end of the loom. unplug the plug, inspect, and replug. see how it goes. if that fails, try and jiggle separate wires and find which wire is at fault.

failing that - if you suspect a broken wire in say the last 5~10cm of the loom - cut it short, and attach a new plug. if there's insufficient slack in the loom, you'll need to cut it short, then re-extend it with new wiring. makes for a fiddly cut-shut job, but not technically difficult.

of course there could be many other causes for the amp to cut out:
*poor groundwire connection
*faulty remote trigger wire connection: this triggers the amp on/off from the headunit; the output wire comes from the yellow mini-ISO plug that connects into the back of your headunit
*fault amplifier

i presume ALL speakers are cutting out at the same time. this would indeed suggest an issue with the amp.

:)
 

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Discussion Starter #3
Thanks for the advice. Spoke with the previous owner - no mods done on the sound system. And yes, all speakers do cut out simultaneously.

Will fiddle with the connector on the amp side - any ideas which wire is which ?:confused:

Thanks again.
 

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AO Silver Member, 155 Lounge Winner 09
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'cut and paste' from the workshop manual of my GT, i have this, which is hopefully the same or very similar to your setup:

pin #1 +30
#2 earth
#3 + woofer 2
#4 - rear speaker left
#5 + rear speaker right
#6 enablement from radio
#7 - front speaker left
#8 - front speaker right
#9 - rear speaker left
#10 - rear speaker right
#11 + woofer 1
#12 - woofer 1
#13 n.c.
#14 n.c.
#15 - woofer 2
#16 + rear speaker left
#17 - rear speaker right
#18 n.c
#19 + front speaker left
#20 + front speaker right
#21 + rear speaker left
#22 + rear speaker right
#23 n.c.
#24 n.c.
#25 n.c.
#26 - front speaker right
#27 + front speaker right
#28 n.c.
#29 + microphone
#30 - microphone
#31 + front speaker left
#32 - front speaker left

these are for 2 plugs (#1-22 + #23-32). the main ones to check will be wires:
#1: main POS +12V powerwire
#2: GND/earth wire
#6: remote trigger wire from the radio, and the other end of this wire in the yellow mini-ISO plug behind the headunit

that is where i'd start. alternatively, the amplifier may be going into 'protection mode' because of faulty speakerwiring or a blown speaker or sub.

it could be hard to troubleshoot, so good luck.

:)
 
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