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General => Car audio => Topic started by: Snap on 27 February 2005, 20:49

Title: New HU but having connection problems
Post by: Snap on 27 February 2005, 20:49
I bought a new head unit and i tried to connect it but having no luck. I followed the instructions given but no joy. I think the problem might be to do with one of the connectors.

1. I think its the auxilory power connector, What does it do?
2. Im confused about:

Continuous power supply & switched power supply - what is all this about?

Car with or without ACC conncetion?? Huh?

My old unit didnt have a yellow cable connectio but my new unit has. What does it do?

My new units connections. The guy at the shop told me to swap the yellow and red, did that and it didnt work, swapped it back and still didnt work
(http://img.villagephotos.com/p/2004-6/744368/hu_2.jpg)


My old unit's wiring and no yellow wires??
(http://img.villagephotos.com/p/2004-6/744368/hu_3.jpg)

Im puzzled, please help a novice.
Title: Re: New HU but having connection problems
Post by: jimbo on 27 February 2005, 23:08
dont fret my friend this is very easy to solve  :smiley:

1. you should have a permenant power (live) conection so that the radio remembers your settings. this is connected directly to the battery or a feed that is always live and not affected when you turn the ignition key off.

2. you will need an suitable earthing point for you earth unless you loom already has one. find a shared earthing stud behind the dash and use that.

3. your yellow wire should be an illumination wire. this needs connecting to the illumination circuit in your dash. this is the ciruit that feeds power to your switches and heater controls to light up when you turn your lights on. if you have a mk2 golf it is the grey and blue wire that runs around inside the dash. this automaticly dims the units display for night time driving when the lights are turned on.

4. ACC conection meens that the radio will only turn on when the ignition is turned to the ACC mark or turned all the way but not turning the engine over. this also meens that the radio turns off when you turn the ignition off so that you cant lleave the radion on when you leave the car. If you want to use this feature you need a supply from th ACC circuit. as i have a mk2 i have used the power feed for the fan swith in the heater controls. this is a ciruit that only has power when the ignition is in ACC position. if you dont want this feature just connect it to the permenat power feed and you can turn the radion on or off regardless of the ignition.

5. a point to remember is that some units will only work if the ariel is connected so make sure you have a good ariel connection.

i hope this help you :smiley: if not just post a photo of the wiring diagram and your model of car and i am sure we can help you out  :smiley:
Title: Re: New HU but having connection problems
Post by: Mr Blue on 28 February 2005, 13:10
connect the red and yellow together on the new wiring. then connect these to the old red wire in the car.

Connect the black wire to the brown or the black (cant see the pic clearly)



BANG!  :laugh:

only kiddin :wink:
Title: Re: New HU but having connection problems
Post by: Snap on 28 February 2005, 14:31
Some more info:

Ok, here goes the new connector supplied with the unit has these wires on it:

c = column

c1       c2      c3        c4
red      blue     0         0
black      0     yellow    0

And it looks like:

(http://img.villagephotos.com/p/2004-6/744368/hu_6.jpg)


The corresponding connector on the car side goes something like this:

c1         c2                c3               c4
red         0                 0                yellow/white
brown     blue/white     brown/red    0

Car side connector looks like:

(http://img.villagephotos.com/p/2004-6/744368/hu_5.jpg)
Title: Re: New HU but having connection problems
Post by: Dizzie on 28 February 2005, 17:41
do what I do. chop the whole lot off and solder it all in :grin:
Title: Re: New HU but having connection problems
Post by: Snap on 28 February 2005, 19:08
Im an electric illiterate so me thinks if i do that, my cars gonna blow up.

Im pretty sure that theres another problem else. If i just swap the yellow and red, it should work but it doesnt. Is there a fuse somewhere (apart from above the bonnet pull) where a fuse could have blown?
Title: Re: New HU but having connection problems
Post by: jimbo on 01 March 2005, 00:15
1. your old loom =

1.red = permenant live
2.brown = earth
3.blue/white = illumination
4.brown/red =ignition live
5.yellow/white = elecrtic ariel

These designations i am quite sure of as they have come out of a bently manual.

Warning the following is only based on assumption and we all know what assumption is the mother of all...........

your new loom =

10.red = ignition live
11.black = earth
12.blue = illumination
13.yellow = permenant live

These are only assumptions but if you post a piccie of the wiring diagram we can tell you for certain? :smiley:

try connecting them in this format:

old loom? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ? ? ? ? ?new loom

1.red = permenant live.........................13.yellow = permenant live?

2.brown = earth..................................11.black = earth

3.blue/white = illumination....................12.blue = illumination

4.brown/red =ignition live.....................10.red = ignition live

5.yellow/white = elecrtic ariel................ not used


Title: Re: New HU but having connection problems
Post by: Snap on 01 March 2005, 01:54
These are only assumptions but if you post a piccie of the wiring diagram we can tell you for certain  :smiley:

Sorry but where can i get the wiring diagram from?  :undecided:

From the fitting instructions it says:

(http://img.villagephotos.com/p/2004-6/744368/hu_6.jpg)

Yellow = continuous power supply
Red = switched power supply
Blue = power arerial control
Black = earth.

Title: Re: New HU but having connection problems
Post by: jimbo on 01 March 2005, 12:48
Sorry matey i ment the wiring diagram supplied with the radio but it dont matter as you have stated what i need to know? :smiley:

try connecting them in this format:

old loom? (car loom)? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?new loom (radio loom)

1.red = permenant live......................... yellow = permenant live (continous power supply)

2.brown = earth.................................. black = earth

3.blue/white = illumination.................... not used

4.brown/red =ignition live..................... red = ignition live (switched power supply)

5.yellow/white = elecrtic ariel................ not used

try that format for starters and if that dont work connect the red and the yellow on the radio loom to the red on the car loom? :smiley:
Title: Re: New HU but having connection problems
Post by: Snap on 01 March 2005, 23:57
Didnt work mate  :cry: I even switched it over and it didnt work.  But when i plugged it in there was a winding noise so power was getting to the unit but nothing appeared on the screen.

What amp should the fuse be for the radio (not the back of the radio but in the fuse box)?

The other connection on the car loom goes like this:

green&blue/solid blue/solid red/green&red
red&brown/brown&blue/brown &white/brown&black


The other connection of the units loom:

1. black&purple/3. black&grey/ 5. Black&white/ 7. black&green
2. solid purple/ 4. solid grey/ 6. solid white/ 8. solid green

According to the instructions:

1&2 - speaker rear right
3&4 - speaker front right
5&6 - speaker front left
7&8 - speaker rear left
Title: Re: New HU but having connection problems
Post by: jimbo on 02 March 2005, 19:04
hi matey :smiley:

the other connectors are for your speakers so thats easy peasy :wink:

you need to check that you are getting power from the right wires. either get a multi meter or get a side light bulb and hold it on the earth terminal. then one by one with the ignition off touch each wire on the bulb and see if it lights up. this will tell you which wire is your permanant live. then repeat this with the ignition in the on postion to see which wire is the ignition live.
once you know these wires try wiring it up to these wires.

where abouts are you based mate?
Title: Re: New HU but having connection problems
Post by: Snap on 02 March 2005, 20:40
Im in N london. Ive got a multimeter so can you take me through how i can use it for this problem.

Ok, so do i turn the knob to speaker mode and put the black lead on the earth (brown wire on the car loom) and red lead touching the wires one by one. When it sounds thats my permanent live (with the ignition off). Then repeat the process with the igniton turned on and see which is the ignition live. Is this right?

This is my multimeter by the way:

(http://www.multimeterwarehouse.com/using%20a%20multimeter_files/meter2.gif)
Title: Re: New HU but having connection problems
Post by: Snap on 03 March 2005, 02:09
Another thing,

Fuse 22: Radio & Cigarette lighter - Ive got a working 10amp fuse in there - bentley manual says 10amp but Haynes says 15amp. Bearing in mind my cigarette lighter doesnt work and my previous units digital bit was unlit (maybe that might be the bulbs). So 10 or 15amp?

Should i check any relays?
Title: Re: New HU but having connection problems
Post by: Snap on 03 March 2005, 22:41
Good news all - IT WORKS!!!!!!!!

I looked at the HU i took off to replace the new one with. It seemed that it only had 2 main wires, earth and live (both permanent live and ignition live) So i modified my new loom accordingly.

I modified the loom from:

(http://img.villagephotos.com/p/2004-6/744368/hu_2.jpg)

To this:

(http://img.villagephotos.com/p/2004-6/744368/hu_7.jpg)

To give:

(http://img.villagephotos.com/p/2004-6/744368/hu_8.jpg)

Thank you all so much for your help.

Title: Re: New HU but having connection problems
Post by: jimbo on 04 March 2005, 19:05
 :laugh: :laugh: woohoo? :grin: :grin:

well glad you got it working matey? :smiley:

just remember where to come for your golf info? :wink: