550 radio wiring

Folks,

It seems that the radio circuit (and interior lights and cigarette lighter) are always on, even with the key off.

Has anyone modified this supply to be switched through a relay to prevent quiescent draw ?

 

There are two power wires to the radio. One is always on (for memory) and one is only on with the key. When I changed my radio, I had to swap these pins in the car’s connector. Swap pins 4 and 7. In my car, there was no wire/pin in pin position 6 for illumination. I had to splice a wire from the keyed power line and add pin 6.

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Shiv, does the 550 lose the pre-tuned radio stations with the battery in cutout? Do you have a standard radio?

I thought the only purpose of having direct battery power to the radio was to preserve the radio stations. If this is the case, then you have to make decision on whether you want a flat battery or keep your stations. Having said that, I'm sure the current draw is quite low for this. The immobiliser will probably draw just as much current.

(EDIT: sorry, crossposted with Ryan)

 

This is great information, I have updated the radio to a Pioneer flip out unit. Thanks.

 

I wonder if the newer Pioneer has a non-volatile memory for radio stations?

 

I can't remember the last time I listened to a radio station, so this won't bother me ! However the wiring diagram shows a constant source for the clock and tuner. I suspect it's reversed exactly as Ryan described. More tomorrow !

 

He's probably correct. Just looking at the 546M wiring diagrams and that also has reversed wiring.

On the 456M, the wire colour is red/green for the battery and green for ignition. Probably the same on the 550.

 

Thanks. I shall tackle this in the AM, since the new radio kills the battery, and it was fine before that. On the pioneer, yellow is constant power (memory), and red is ignition.

 

So as not to confuse anyone, the pinout I posted a few posts earlier is for the aftermarket radio I installed. Here is the pinout for the original Becker unit, you can use this to determine which wires goe where in the car’s connector. This is for a 2001 USA 550.

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In my car, the yellow and the red wires from the harness are always 12V !! Key makes no difference. As a result the radio is always pulling current and killing the battery.

 

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@Qavion @AVIMAX Does your interior light, map lights and cigarette lighter outlet stay on even when the key is off ?

I'm trying to figure out if the previous owner hotwired the switch somehow or if I have a bad switch.

 

Unfortunately, I don't have a 550 and I'm having trouble identifying that (original) plug. Half the diagrams are missing in the workshop manual (digital copy).
Having said that, interior lights should have power permanently. Cigarette lighters usually do.

Is that a 13 pin plug? Do all the wires go to the 3 plugs on the radio? What colour wires are on the other side of the plug to your yellow and red power wires? Wire colours sometimes give away their power sources.

Would you be able to draw a plug (add numbers from 1~13) and list the colours on both sides of the plug as best you can. This will be extremely useful down the track. Specify whether you are listing the colours as seen looking at the pins and sockets or looking at the wires at the rear of the plug halves.
In some Ferrari plug pinouts, the plugs look like this (I usually add colours with the little dot in the centre of the pins representing the stripe colour).

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Are those pen markings on the wires in your photo your markings?

Fuse 22 in the footwell is labelled "Radio". I assume that provides hot battery power (for the radio memory). You could try pulling the fuse to see if you still have power on the red and yellow wires.

 

My map light and cigarette lighter work with the key off, the interior light works but turns off after a few seconds when the door is closed. The connector in your photo does not look familiar, maybe it is further downstream from the radio. The unit I installed used the same connectors as the original Becker unit.

 

Just reread your message above the post with the photo, missed it before. If yellow and red wires are for pins 4 and 7 in the original connector, something is not right if both are hot without the key. Did you cut off the original connector that plugs into the original radio? Do you have it? Can you check it to see which colour wires are in pins 4 and 7 to confirm (if you didn't already).

 

@Qavion The feeder colors on the other side of the connector are red/green and red/blue or red/black, I won't see them clearly until I remove the console today. Those markings are on the wires, I didn't mark them.

@AVIMAX I need to find the OG radio (it's in a box somewhere) but the fact remains that both those 2 wires are always hot. I probed all the wires, and those are the only 2 that get 12V, key off or on.

 

From the WSM, the radio doesn't appear on the key list

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Can't promise anything, but if I have time tonight, I'll pull my radio and check the colour of the 2 power wires and confirm the colour that is powered by the key.

 

Thank you !!

 

Thanks, Shiv.
Red/green is typically a hot battery wire. Red/black is hot battery power, too (e.g. the cigar lighter). The only Red/blue wire I found was for the secondary air pump.

I'm not sure why there would be two (hot) battery wires.

There are some variations to the colour schemes. There are red/black wires on the engine harnesses (i.e. left and right bank fuel injector wires) with power controlled by the Motronics ECUs, not direct battery power.

That list you posted may not tell the whole story. For example, the ABS/ASR is shown as ignition powered, but there are some wires in that system which are hot all the time (waiting for an activation signal from the ABS/ASR ECU)

 

It is my current belief that the radio is unswitched from the key. The older radios, when you turned them off, they actually went off. The Pioneer is a computer and only goes into standby and draws over 800 mA. The trick would be to find a switched wire for say, the instrument panel and use that to trigger a relay. Hence I am keen to hear from @AVIMAX if this is normal or a fault condition on my car.

 

I checked my wiring. White with a green stripe is the switched power and red with a green stripe is the permanent power. The connector in your photo I cannot find in my car. Was you original radio a Sony or a Becker? Mine was the Becker.

 

Mine was a Sony. Thanks a lot for this information. I really appreciate it. My car is a 99 US spec.

 

Shiv, are any of your wires white with a green stripe? It's hard to tell from your photo. The only white/green wires I could find in the diagrams were related to the HVAC system (not ignition). Ryan, are you sure your switched wire isn't green/white rather than white/green?

 

Ian, no. They must have changed the harness in the later cars - there were changes in 00 because of OBD compliance.