harness...

[mike6786]

i just bought an aftermarket HU from this guy on ebay and he is including a wire harness. will I be able to use this wire harness in my 95 318i? or do I have to buy a new one that is specific to my car from circuit city? please help.

[El Presidente]

what did he say about the harness? All HUs I'm familiar with come with their own harness, but it has to be wired to an adpter harness for the factory deck.

[jllphan]

Prez is correct. You take the wiring harness suplied with the new aftermarket deck and soder or crimp it using barrel connectors to the other harness you buy from CC or somewhere like that. The one below is made by metra, and i believe it is a part no. of 70-8590. If the guy includes one of these then bully for you!!

[mike6786]

ok i just came back from CC and got the wire harness and atenna adapter. antenna is a gimme but how do I connect the deck's harness to the netra harness. all these wires...and I don't know what to do with them...HELP!

[mike6786]

ok i've looked at both harnesses and basically I would have to color match the wires by crimping them together. if this is so, then I won't be using 2 wires (the pink and blue/white wires). but I have done some research and found out that some people hook up the blue/white wire from the HU to the blue wire on the Metra harness to turn on the factory amp. are there any advantages doing this?

[El Presidente]

hooking up the blue/white wire give the antenna more power. Also, the wires will say what you are connecting to. Maker sure you double check the wording and don't just go by color.

[mike6786]

does anyone have the wiring diagram that I can follow?

[jllphan]

Hey buddy! Sorry, i dont check this section that often (audio/video is my vocation and has been for more than a decade) as cars have kinda always been my escape.

The metra harness pretty much match up by color. What prez was saying wuz that often times the aftermarket deck will use yellow as constant +12 and the red will be the sitched/ignition.Yes you will not use all of them. Power antena, amp turn on, illumination, etc. do not necessarily need to be interfaced. If you tell me model # and manufacturer i'm sure i could tell you EXACTLY how to do it. Hope this helps...

By the way, i believe the solid blue wire is the amp turn on, the blue/white wire is usually the power ant.

[mike6786]

its an alpine 7894. I thought I said it was..guess I didn't. I got it because i've heard so many great things about it. if it's just a matter of color matching...I hope to get it in this sunday.

[El Presidente]

great choice. Now that you mention its a 7894 though, Alpine reccomends that this HU be connected directly to the battery like a real amplifier due its 240W output. It doesn't have to be, so it's up to you if you want to run a power wire. I'll be honest, mine is not, and it still sounds great. As said, to wire the alpine harness to the adpater harness all you need to do is match up colors (and double check the wording on the wires matches) and just plug them all together. then you just need to remove the factory HU, install the sleeve and secure it in place, install the alpine and trim ring and you're done.

[jllphan]

Yeah, no reason to hook up constant power to the battery. That's a stupid idea. i dont know why Alpine says to do this. hooking it up to the battery is a nonregulated power supply and in certain circumstances, hooking your hu up that way could be a big mistake! not only that, but its not like the Alpine harness is 10 gauge wire or anything. You can only draw so much current through a 18GA wire!!


Oh yeah, the 280w internal amp is a peak rating. It will never truly produce that much power. It's more like about 26x4 RMS. This is certainly enough to push your stock speakers and even some aftermarket speakers.

[mike6786]

ive just finished installing my new HU in and it sounds awesome! now I can use that 50 bucks I saved on getting it "professionally" installed for . thanks guys for all your help. I really appreciate it.