Car Stereo Removal

The BMW Business radios have a little flap on the left and right, which when prised open, reveals an allen-key hex head screw. Undo each screw all the way anticlockwise and then the radio should be free to be pulled out. The antenna wires on the rear can be unplugged, and then the main connector disconnected. The latter has a slide-locking mechanism, which needs to be grabbed by the sides and pulled upwards. This will simultaneously lift the connector off the back of the radio. Careful with this, as it can break.

You will then need a BMW (round-pin) to ISO adapter (ebay $5) and with this you can then plug and play any new radio with an ISO connector.

If you have the BMW Professional radio, the actual receiver is in the boot, mounted on top of the amplifier behind the fold-down panel. The dash contains the cassette unit and the display.

Just as Arnie says and shown in pictures here:

http://www.meeknet.co.uk/e31/B…g_Becker_Indianapolis.htm

I'd just add that if you're unlucky, the old radio may foul on the inside of the console - there is a lip that you can't see if the radio is fitted and sometimes the radio will catch against this and prevent you from sliding the unit out. If this happens, get yourself something to slip under the radio unit to help it clear this obstruction - something like a car filler spreader might do the job - you can get plastic ones that would avoid making any scratches. Or you could use something like a thin piece of plastic cut from an old margarine box or similar. Ask me how I know....

I think Revtor posted some pictures of the obstruction - I'll have a search and if I find them I'll post a link
Cheers,
Jason

Argonaut: I don't recall posting an image of the radio opening, but the problem with getting the head unit out is usually with the retaining mechanism itself getting stuck on the lip that is inside the radio opening to prevent the radio from dropping in too deep. Just drop the unit a bit back in the opening, play with the screws and try again. Eventually it will come out. I fixed this annoyance by gluing plastic inserts to the sides of the radio opening with exactly the sample thickness as the lip. That way the retaining mechanism can never expand wider than the lip and thus never get stuck...

Note also that the original radios have a long plastic prong that sticks out from the rear and which engages in a hole at the rear of the radio carrier in the dash (just visible in Tim's pics). This provides additional support and keeps the radio lined up correctly without stressing the front of the radio cut-out in the dash. The plastic prong can be unscrewed from the old radio and used on the new radio, if that has a provision for it.

Radio replacement Clarion nz502e in BMW 840Ci

Hello Timm,

thanks for that great step-by-step tutorial and in general for your great website on all kinds of works and repairs.

I will try to replace the stock Business CD Radio with a Clarion nz502E unit in my 1994 BMW 840 Ci. Anything I should know on how to place the junk of cables coming with the Clarion nz502e behind the Radio MDI area?

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