About Josh Fields Expertise I can answer questions related to the BMW e30. These are the cars produced from 1984-1991 (1992 for convertable) in the United states. I am more fluent with the six cylinder models, although few things changed for the 4 cylinder cars. I know most of the problematic areas of these cars, and have found ways to fix them.
Experience I have owned six different E30's over the last 10 years. I do all my own work, and know about ever nut and bolt on these cars.
I would like to replace the car stereo on my 91 318is (E30) I seem to recall from my 87 535i (E28) that the grounding system is different. In short is there an adapter that will allow me to plug a modern stereo into the wiring or do I have to rewire the whole system?
Thanks,
Seth
Answer Seth,
The stereo wiring on these late-80's BMW's is different from most cars that I have seen. On the back of most aftermarket head-units there are two wires running to each speaker. Most head-units supply wires for 4 speakers, so you would have 8 wires. The BMW head unit only has 4 wires... 2 for each side of the car. The rear speakers are wired to the front speakers, and the front speakers get their signal from the head-unit. So in order to take full advantage of a new head unit you will need to run your own wiring. You would need to run two wires to each of the rear speakers and you could use the existing wires for the front. However you will need to disconnect the wires running from the front speakers to the rear. If you do some searching on the internet you could possibly find a harness that will plug into the existing speakers, however I dont think you'll have much luck as the stereo and the car will use different wiring.
