aftermarket headunit

D

dave1709

Wrench Pro
Points
61
Location
Highlands(scotland)
Car
A4 2.8 V6 Quattro
hi guys, i've just put a new headunit into my car and am having a couple of problems with it.

firstly, i have amplified rear speakers and they are not very loud with the new headunit installed

secondly, the headunit doesn't seem to remember any of the settings i change once i take the key out the ignition.

Can anyone help me out?????
 
The head unit's forgetting the settings because the the battery remote lead isn't connected, it's normally a very thin lead (possibly blue & white) sometimes with a tiny in line fuse, if it's fused check the fuse.

Speakers: Did just swap the ISO plugs from one stereo to the other or did you wire it by hand? if you did the latter you may have got the polarity wrong. Also, check the head unit settings to & make sure the fader & balance are centered & the mute function isn't on. Sounds daft I know but it can happen! :lol:
 
Loz said:
The head unit's forgetting the settings because the the battery remote lead isn't connected, it's normally a very thin lead (possibly blue & white) sometimes with a tiny in line fuse, if it's fused check the fuse.

Speakers: Did just swap the ISO plugs from one stereo to the other or did you wire it by hand? if you did the latter you may have got the polarity wrong. Also, check the head unit settings to & make sure the fader & balance are centered & the mute function isn't on. Sounds daft I know but it can happen! :lol:
Click to expand...

Nearly right mate for the settings to save you need to swap the red and yellow wires over;)
 
there was one wire with an inline fuse but im pretty sure it was't the blue one,will check it anyway just incase. i did have to connect a blue and white wire from the adapter to the blue wire coming off of the headunit?

as for the speakers, i used the pc9 401 harness adapter to connect the new headunit to the audi wiring. when the fader and balance are centered the front speakers work as before but the back speakers, although they do produce sound, are very quiet.
 
just swapped the wires about and problem 1 solved.cheers herb. now for the rear speaker prob. the blue and white wire on the adapter that i connected to the blue wire on the head unit turns the rear speakers on. could it be that the signal the headunit is sending is just too weak to power the built in amp in the speakers?
 
just to clarify things you have added a amp and its turning on yes?
have you checked the gain on the amp??
 
no no amp yet but thats the plan. the instructions that came with the harness adapter said the blue wire from the headunit (the amp remote) needed to be connected to the blue and white on the harness. when you have the headunit on and disconnect the blue wire from the harness adapter the rear speakers turn off completely.
 
im just wandering if your car has amps as standard?
what year is your car ill see what i can find
 
Yeah it has but only for the rear speakers. apparently the standard headunit powers the front speakers and sends a preout signal to the amplifier which is built into the rear passenger side speaker which powers both the rears.have been googling it all afternoon and have only found people with the same problem but no solutions.
 
dave1709 said:
Yeah it has but only for the rear speakers. apparently the standard headunit powers the front speakers and sends a preout signal to the amplifier which is built into the rear passenger side speaker which powers both the rears.have been googling it all afternoon and have only found people with the same problem but no solutions.
Click to expand...

Usually the way:(
Did your standard unit have a amp preout?
 
no, it didnt have the red and white sockets.that wouldve been handy though,save me all this hassle.haha from what i have read the standard unit basically has its own amp remote which activates the built in amp which powers the rears.
 
I Just looked at the PC9 401 harness adapter, it's used to supply an RCA out when one isn't available. Do you have a part of the adapter you haven't used hanging out the back of the head unit?

I'm wondering if you've separated the pre-out from the Audi loom. There is a PC9 404 which may have been better suited possibly? :confused:
 
Loz said:
I Just looked at the PC9 401 harness adapter, it's used to supply an RCA out when one isn't available. Do you have a part of the adapter you haven't used hanging out the back of the head unit?

I'm wondering if you've separated the pre-out from the Audi loom. There is a PC9 404 which may have been better suited possibly? :confused:
Click to expand...


no but there is some of the original audi wiring doing nothing. the big red one is for phone connection and there are 2 mini iso connectors one for the cd changer and the other one is for the dash display.

the new headunit has preouts so that cable wouldn't be needed.

Herb, yes i know where the amp is,it is built onto the one of the speakers in the back. have found a possible solution on this site

www.vwaudiforum.co.uk/forum/showthread.php?t=54453

sounds like a fair bit of work though to rewire the rear speakers straight to the headunit.any thoughts?
 
dave1709 said:
no but there is some of the original audi wiring doing nothing. the big red one is for phone connection and there are 2 mini iso connectors one for the cd changer and the other one is for the dash display.

the new headunit has preouts so that cable wouldn't be needed.

Herb, yes i know where the amp is,it is built onto the one of the speakers in the back. have found a possible solution on this site

www.vwaudiforum.co.uk/forum/showthread.php?t=54453

sounds like a fair bit of work though to rewire the rear speakers straight to the headunit.any thoughts?
Click to expand...


How easy are the panels to remove?
 
dave1709 said:
no but there is some of the original audi wiring doing nothing. the big red one is for phone connection and there are 2 mini iso connectors one for the cd changer and the other one is for the dash display.

the new headunit has preouts so that cable wouldn't be needed.

Herb, yes i know where the amp is,it is built onto the one of the speakers in the back. have found a possible solution on this site

www.vwaudiforum.co.uk/forum/showthread.php?t=54453

sounds like a fair bit of work though to rewire the rear speakers straight to the headunit.any thoughts?
Click to expand...

new speaker wires will be easy mate dont look at this pic to much it will cabbage you!!
B6rear-subpinout.jpg

looking at the last post macsub talks sense!! the hu will be more powerfull than 2x20w amp

so me personally i would keep the original loom in tact, disconnect the remot wire, add some half decent speaker wire from the hu to the speakers via scotch locks! (cheap also keeps your original loom in tact so when you come to sell just put the original hu back in;))
 
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