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Discussion Starter #1
As above, my 156 (2001) has always had a aftermarket headunit, I recently purchased a original Alfa radio/cassette headunit and fitted it. All works fine except...................


......after 20ish minutes the headunit switches off, now I appreciate its not the end of the world but it is annoying, does anyone no why?


Or how to rectify?

I dont have the instruction book for this headunit.
 
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Discussion Starter #2
Forgot to say, it does'nt turn off with the ignition either.
 

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As you had an aftermarket radio before, the permanent and switched +12V signals are probably reversed.
(In the standard alfa radio's they are reversed compared to the "standard" iso configuration. This was probably changed when they installed your aftermarker radio, so now needs to be changed back again ;))
 
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Discussion Starter #4
I swapped the 12+constant and 12+ign around (pins 4 and 7 IIRC), this left me entering the radio code in when i turned the ign off???
 
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Discussion Starter #6
I'll print this off and have a go tomorrow.

Cheers for the link.
 
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Discussion Starter #7 (Edited)
No probs.

Oh and just checked audio manual - seems standard head until will switch off automatically after 20min if switched on without key at MAR. Presumably to stop draining battery by leaving radio on
 

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No probs.

Oh and just checked audio manual - seems standard head until will switch off automatically after 20min if switched on without key at MAR. Presumably to stop draining battery by leaving radio on
Thinking about it, the standard HU actually doesn't have a +12 switched connected, only a permanent +12. Switch on/off is controlled via the CAN bus. Hooking up a switched +12 probably screws things up....
Check that:
a) the can bus is still connected
b) permanent +12 is connected to the right ALFA location
c) switched +12 is left not connected
 
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Discussion Starter #9
jwq

You might be right about switched +. I'm sure my buddies 156 only had perm+. Did the early 156s have can bus, didnt think it did ?
 

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jwq

You might be right about switched +. I'm sure my buddies 156 only had perm+. Did the early 156s have can bus, didnt think it did ?
Good point, I'm not sure about CAN on the 156. For the 147, the connections are:
A-BLOK
A1 = CAN
A2 = booster in
A3 = CAN
A4 = -
A5 = remote +12V out
A6 = -
A7 = +12 V continuous
A8 = mass
 

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AO Silver Member, 155 Lounge Winner 09
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pre-update 156 has no CANBUS, agreed. :) but doesn't the update (dash) version have CANBUS?

as per 147DAV, it is a standard feature for a factory headunit to power down after 20min if the ignition is off. is this when it's occurring? or is it also occurring when you are driving?

the feature can be switched off or a different time period set.

:)
 
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To update - problem solved, pin 3 required the 12v ign, which on a previous installtion had been put to earth.

Radio will sw off after ign off
It doesn't (anymore) sw off after 20 mins with the ign on.
The radio has the socket for CAN bus
The car doesnt have CAN bus to the radio.

The radio doesnt sw off with the ign regardless of whether it was turned on when the ign is on or off, is this normal?


pre-update 156 has no CANBUS, agreed. :) but doesn't the update (dash) version have CANBUS?

as per 147DAV, it is a standard feature for a factory headunit to power down after 20min if the ignition is off. is this when it's occurring? yes (was and still is)or is it also occurring when you are driving? It was but is no more

the feature can be switched off or a different time period set.HOW?(no manual)

:)

Thanks for all the help.
 

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The radio doesnt sw off with the ign regardless of whether it was turned on when the ign is on or off, is this normal?
Yes, assuming it is the same idea as the original 156 radio, if left on the radio will switch itself off 20minutes after the ignition is turned off.
 

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AO Silver Member, 155 Lounge Winner 09
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To update - problem solved, pin 3 required the 12v ign, which on a previous installtion had been put to earth.
pin 3? normally it would be pin 4. :) bizarre it had been earthed before!

changing the 'time till headunit switches off after turning off the ignition' is a CANBUS feature. sorry, it seems you cannot alter this; i misinformed you. :tut::D

:)
 
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