New Body Gem - Factory Radio - Wire Harness Info

GEM Forum
1

Hi,

I have a 2022 E4 that came with the upgraded stereo and speakers. That radio sucks and I am in the process of upgrading it to a Boss 7” floating display with wireless car play. Also adding a small amp and sub.

After removing the radio, there is a harness with two plugs. One I can tell contains the speaker wires. I have a strong feeling the other plug is the positive, negative and constant. I just don’t know which one is which. Would like to tap into these for the radio versus extending the wires to reach the terminal block.

Please post if you can help.

Cheers :clinking_beer_mugs:

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2

Black is probably ground. Key off test each red to frame, one should light up your test light.

Turn key on, see if other red lights up the tester.

Check continuity between black and frame with dvm. Have someone else hold one of the leads or clip it and dont touch it or cross the wires.

3

I was able to figure it out. Just decided to unwrap the factory tape a bit till it went to the oem terminal black.

Terminal Block - Left to Right = Positive , Ground , Accessory

Brown = Ground

Red w/ White Stripe = Accessory

The radio has a yellow wire labeled “Battery” so I ran a wire to the Positive post on the Terminal Block.

4

Yeah i was wondering why the guy who built a 50mph belt drive thunk was befuddled by 3 wires with two possibilities per wire.

Thinking “this guy has to yanking our chain”

5

Hahahaah. Been out of the “GEM Game” for a while and just wanted to be sure. But I appreciate the call out.

Now for this reverse wire….. any idea which one connects to the purple on the radio to tell it the gem is in reverse.

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6

So it can play the song backwards?

If you put on DSOTM youll never get out of reverse…