Headunit not working - fixed

[Bruceybaby 0]

Having problems with the wiring in my Rado. I've tried 2 different HU's in it and neither seem to work. The ISO plugs dont work, and the wires dont seem to match their 'job role' where they meet in the block connector. Although i had been trying to use the ISO blocks, as they were not working. I've resorted to connecting the wires directly to see what happend. Using the information below.

 

http://www.the12volt.com/installbay/ste ... /2166.html

 

Constant 12V+ Red/White

Switched 12V+ n/a

Ground Brown

Illumination Gray/Blue

Dimmer n/a

Antenna Trigger White/Blue

Antenna Rear Roof, Amplified

 

 

matching the above wires with the wires on the HU, using the wiring diagram that is on the HU; I connected the Constant 12v, and the Earth. the illumination W/B was connected to the HU marking Light Switched. and the Antenna trigger was connected to the blue wire on the HU marked Antenna/Amplifier.

 

That takes care of every wire on the HU block that isnt for the speakers, except for the ignition switch wire, which . . . .I don't have a wire for, and as the above says.

 

there isnt meant to be one?

 

Still i get nothing from the HU. The Multi-meter shows 11 point something or other volts when connected to the constant live and ground. So i'm presuming there are no other issues.

 

Checked the fuse at slot 22. ( a 10a?) which was fine, as i slotted it back in, the HU lights up, then quickly shuts off again. Basically, it lights up as you begin to put the fuse in, then cuts off. no matter where the fuse is.

 

 

I've now reached my maximum ability in diagnosing this problem, and i need help :(

 

Cheers

 

Bruce

[revilo 0]

My head unit hasnt got a switched wire,its all controlled from the head unit itself(i.e. The source button.) and its never caused me any issues apart from forgetting to turn it off.

What rated fuse are you using?Sounds like you need a higher rated one.check what fuse your meant to have.

[Bruceybaby 0]

Its a 10a mate. anyone know what its meant to be?

[revilo 0]

Ill check mine tomorow and let you know unless someone else does before!

[smee 0]

Right, from the owners manual:

 

Red - Permanent live

Brown - Ground/negative

Brown/Red - Switched live (ignition)

Grey/Blue - Instrument panel lighting

Blue/White - Speed signal for automatic volume

 

So the description you've got seems to be wrong - looks like you've only got the switched live connected. Also DON'T connect the blue/white wire to anything as it'll stop the spoiler working - same if it shorts to ground as well. The radio fuse is a 10A. The Corrado's own ISO plug doesn't correspond to ISO standard, either, the switched and permanent live are swapped round, and if yours has a powered antenna like my old G60 did, there'll be a black wire from the ISO to the aerial lead. Only VAG stereos have an output to power this, but tbh the amplifier in the aerial base has probably long since died so it'll make no difference anyway. There's a description somewhere on the forum of how to open the aerial up and bypass the amp. Later cars don't have it at all (presumably because VAG realised that they don't add much and just fill up with water and corrode!) The wiring colours remain the same for all rados, but the later the car, the less info the owners manual gives you... :brickwall:

 

Edit: Just looked at that website you mentioned above - it's totally wrong.

[Bruceybaby 0]

Thanks for your reply SMEE, I had another go today with a cooler head, took everything apart and started again and its working now.

 

Although my dash illumination lights have now gone out :censored:

 

Are you sure about all rado wiring being the same across the board? I constantly come across varying diagrams for early and late rados. The colour code i have seems to tie in with whats in the car :scratch: although i do have a spare black wire now that you mention it. . . . . .

 

thanks again!

[smee 0]

Well I've had a 91 and a 95 corrado, and the wiring colours were identical between them (though my VR doesn't have the black wire for the powered aerial) but I'm wondering is your corrado a really early one (90 or earlier?) Didn't mk2 golf wiring change in 1990, maybe it's the same deal... I'll have to have a look in the Bently bible.

 

Edit: Just looked on the 12volt site again, in case the page for corrado 92-on corresponds to what I have. It doesn't. I'd take their list with a pinch of salt tbh.