Metra Harness, 88 BMW 735i / Nakamichi

I am installing a Nakamichi TD-500 head unit in an 88 BMW 735i.

Which Metra Harness do I need?

Are there other adapters, brackets, pig tails I may need?

Thanks,
- CarlD   trimagna@yahoo.com

There are no harness'  for this vehicle and there are factory amplifiers in it with common ground inputs. You will have to bypass the amplifiers by running new wires to each speaker and put an amp on whatever speakers the radio cannot handle (i / e, more than four not including tweeters). No kit required.

The Nakamichi head unit has pre-amp outputs. I've been advised that I should keep the BMW amp in the circuit and adapt the connector on the Nakamichi to the existing BMW plug.

I have the pinouts for the BMW plug but I would prefer to buy a harness. Circuit City lists 4; JVC, Alpine, Pioneer and Sony. Presumably there are more, or possibly one of the above is easily adaptable.

I have been unable to connect with the website, MetraOnline.com. If there other selection guides, please advise.

Thanks,
- CarlD trimagna@yahoo.com

There is no harness for this vehicle unfortunately but what you can do if you have the schematics is solder rca's on the the input wires going into the amp, and then you can use it with that preamp deck. Now in 1990 they did use standard harness', but not pre 1990. Those old BMW's had multiple smaller plugs and were considered factory hardwired. The input plugs were the two rounded plugs that had just one pin in each receptacle. Those were the positives and the negative is chassis.

I posted the image of the OEM radio from the backside. https://www.intergate.com/~trimagna/images/735i_User_Manual/BMW_radio_back.jpg

That would be a 90' and newer BMW radio. Metra makes a harness you can buy that will keep the amps active. 70-8591

Also, please check this document.

https://www.intergate.com/~trimagna/images/735i_User_Manual/StereroConnector.pdf

Will you please look on the drivers door or by the door stryker for a sticker that has info on your vehicle as far as month and year of your vehicle and type and let me know.

Upon further looking at the plug you have I noticed something I have not seen before. Your inputs are not where they normally are on 90' -01' 7 series radios. Plus the system you have should not exist on a 88' BMW. Those were factory hardwired in those years. It seems you have a special edition BMW which I have seen many before so I completely believe you. I would have to say that in your situation I would either try to get schematics on the input of the amp (which is near impossible unfortunately), or install a multi channel amp. Installing the amp will cost more but will give you much better sound and less of a headache trying to figure out the factory amp input . 

This MTX amp is pretty good: https://www.cardomain.com/item/MTX404 Your factory speakers won't last long on it though.

Do you know how many speakers you have and if one or two of them are subwoofers? I'm assuming you have ten as that was the premium in 90' and that's what your vehicle seems to resemble. If that's so, it would be mid and tweets in the rear (4), and low, mid, high in the fronts (6) that is configured to work from a 4 channel amp with passive crossovers built in the speakers. If that's so, any decent 4 channel amp with 35 to 50 watts per channel would work fine. Having a high pass crossover for the rear channels would be nice also but not required. I don't recommend product as what I like the next Joe may not. Your best bet is to go into a local shop that carries 4 channel amps that are hooked up on display so you can hear the difference yourself and judge.