Confusion with Head Unit Install

[KnotSoo]

I am attempting to install a head unit in my 1992 240SX. The car is not equipped with the Active Speakers system. There is no unit installed at the moment. This is what is visible behind the dash: a larger harness with nine wires attached, a smaller harness with three wires attached, a red/yellow stripe wire with a small black connector at the end, and four loose/snipped wires (lavender, pink, red, green). I purchased an installation adapter which includes: a larger harness with ten wires attached and a smaller harness with five wires attached. As you can see, the number of wires that are attached to the male/female ends of the harnesses don't correspond. Can someone please identify the four loose/snipped wires behind the dash and why the factory harnesses and the adapter harnesses don't correspond? Also, which wires are associated with the gauge clock and the dome light not functioning? I would really appreciate any input. Thanks!

[[s3]]

If someone cut the original harness, you have to re-solder the wires to your adapter.

It might be that you bought the wrong adapter, the ones I buy from Crutchfield are direct fits and plug and play.

[Slippery S14]

It sounds like you have the right one. if they fit together then you should be golden. The loose wires, I dont know what they would be but shouldnt have anything to do with the radio/speakers. The number of wires in the harness compared to the nissan harness shouldnt be an issue. You should compare the harness layout(should be a def of wires on the harness package) and see which ones the nissan harness doesnt have. If its nothing important there you go. I can tell you that the 93 i have has those 2 harnesses.

Those are the steps I would take. I am not sure what the wiring is for the dome light etc. I would check fuses first(if you havent already) as I am pretty sure those end up on the same circuit.

Edit: I am pretty sure the wire differences have to do with that wiring harness being used in more than just 240s...other nissans have other features that the 240 wouldnt have wiring for. Oh and definitely tape up those 4 wires before fooling around too much until you find out what they are for.

-Slip

[Camel]

you have a blown fuse, or multiple blown fuses. cap any exposed wires. check the factory harness at the back for cut wires. plug it up and wire it, ground it to the chassis because the ground is non-existant. the wires don't always match up because the harness was made to fit all nissans of that model year, some of which have other wires that you don't. you will notice that the yellow, red, blue, and black do match up as well as the speaker wires. don't worry your all good.

[KnotSoo]

Thanks for your replies, but I am still not clear on this subject. It seemed that the ports in the factory harnesses that don't have prongs would line up with positive or negative wires for the speakers on the adapter harnesses. The adapter harnesses are correct. They are labeled "NISSAN 1984-94." Also, I have heard that the gauge clock and the dome light are associated with the wiring of the head unit. Any further clarification would be appreciated. Thanks in advance!

[Camel]

dome light and gauge clock is on the same constant 12v+

[dak2007]

the lose wires are speaker wires. in my 91 lavender is right rear (+) pink is right rear (-) red is rear left (+) green is rear left (-). if you want to straight wire it to the head unit use this site for the wire colors http://www.bagotronix.com/nissan_240sx_stereo.pdf :spam

[Camel]

dak - that document is definately shadetree but it does give him the wiring colors.

Never cut a harness that you can get a plug for (or you will leave someone like dak to deal with it when he buys the car, just ask dak about his, blown fuses cut wires and all, much easier with a harness.)

Never cut an antenna plug, the guy that wrote that is an idiot. A 10 dollar adapter can fix this from any local stereo shop. Metra kits/wiring harnesses/adapters are what i used to use. They work every time.

[dak2007]

yeah i know all to well about a cut wiring harness. took me forever to get my stereo installed. i was just sayin that cuz the 4 speaker wires are already exposed.

[KnotSoo]

Can someone please type a list of the factory wire color descriptions and what the wire's function is? My computer does not supply the program needed to view PDF files. So if someone could type an accurate list in a reply, I would appreciate it.

[Camel]

WIRE COLOR FUNCTION WHAT IT DOES & HOW TO CONNECT ITLIGHT GREEN AMPLIFIER POWER This is an output from the unit. When turned on, the unitshould apply +12V power to this signal. If you have theNissan premium sound package, its amplifiers use this signalto control their on/off state. Connect this to the ANTENNAPOWER output on the new unit.RED REAR LEFT SPEAKER +GREEN REAR LEFT SPEAKER - DO NOT CONNECT TO GROUNDVIOLET REAR RIGHT SPEAKER +PINK REAR RIGHT SPEAKER - DO NOT CONNECT TO GROUNDBLUE +12V ACCESSORY This is the main power input to the unit. It is active onlywhen the ignition is in the ACC or ON positions.RED W/YELLOW STRIPE ILLUMINATION - NOT USEDRED W/BLUE STRIPE ILLUMINATION + NOT USEDBLACK W/RED STRIPE ANTENNA POWER This is an output from the unit. When turned on, the unitshould apply +12V power to this signal. The power antennauses this signal to control its up/down state. Connect to theANTENNA POWER output on the new unit.RED W/BLACK STRIPE +12V BATTERY This is the backup (memory and clock) power input to theunit. It is always active.BROWN W/WHITE STRIPE FRONT RIGHT SPEAKER +BROWN FRONT RIGHT SPEAKER - DO NOT CONNECT TO GROUNDBLUE W/YELLOW STRIPE FRONT LEFT SPEAKER - DO NOT CONNECT TO GROUNDBLUE W/WHITE STRIPE FRONT LEFT SPEAKER +BLACK (DOES NOT EXISTIN CAR’S WIRINGHARNESS)GROUND This is the ground connection for the unit. It should beconnected to the car’s metal frame. The shifter boot retainerring is an ideal place to attach to.If you don’t mind cutting into the car’s wiring, you can cut off the rectangular plastic connectors and attach the head unit wires

[Camel]

that was pasted from the pdf. not my information. i make no claims that it is right.

[dak2007]

it's right...the pdf is what i used to straight wire my unit and it was exactly right