Wife bought me a new head unit and I really don't want to pay $120 for best buy to install it. Some nice TWWers have offered to do it for much less, but I thought maybe I'd post here and see if I can get some helpful advice to try and do it on my own. I think I understand just about everything except the wiring. Can anyone explain to me how a wiring harness works and what kind of wiring effort is needed to install a stereo? Am I correct that I would purchase a wiring harness specific to my car, and then connect that one to the harness provided with the stereo? And then I would be able to just plug it right in?

12/19/2011 7:33:56 AM

Yes, get a vehicle specific wiring harness. However, many harnesses may not be wired for options such as: navigation, door chime, steering wheel stereo controls, etc.

Take the harness and solder (or use butt connectors and electrical tape; I prefer & recommend soldering) to the HU's wires, per the harness's instruction page/wire colors (pay close attention to these). Once all that needs to be connected (not all wires will be used) is done, then cap the leftovers, plug the aftermarket harness into the stock harness, connect the antenna cable (assuming stock fits, as you said in classifieds), and the rest is just the dash kit.



[Edited on December 19, 2011 at 9:01 AM. Reason : \/ oh yeh, cap/tape off unused wires, tie them out of the way]

12/19/2011 8:50:13 AM

Generally, you can just match up the wiring colors and/or functions - the head unit will often break out wires that can go to other things like amplifiers or power antennas, but those can just be capped and tied out of the way. What is the head unit and what vehicle is it going into? Did you buy it from somewhere like Crutchfield that includes all the wiring, adapters, and vehicle-specific instructions with it?

12/19/2011 8:54:39 AM

I didn't buy it from crutchfield, it was a gift from my wife, I assume she just bought it at best buy.

The head unit is this: http://www.amazon.com/Kenwood-KDC248U-Dash-Head-Stereo/dp/B004EG0LS2

And it's going into a 2003 Altima. I think I have just about everything figured out. I guess the only part I'm still somewhat sketchy on is that when I looked up the harness that I would need on crutchfield, it said that the harness doesn't have a ground wire and that I would have to ground the new radio to the vehicle chassis, no clue what that means really.

Maybe my best bet would be to return the head unit to best buy and buy one off of Crutchfield with the installation guide and everything.

12/19/2011 9:12:53 AM

I would do that simply because it comes with absolutely everything you will potentially need, and the CS is dead reliable. They test fit equipment into tons of vehicles to ensure that you end up with all the adapters or harnesses you will end up needing, and include instructions with pictures of your vehicle.

On top of that, they have knowledgeable customer service techs in case something isn't as expected. For example, I was installing a unit in my old Hyundai that (unbeknownst to me) had a powered amp speaker system from the factory. Turns out, you have to relocate one wire on the harness to activate the amps in that setup, so the tech walked me through the process and verifying that it worked.

12/19/2011 9:53:04 AM

yeh, crutchfield, while a little more expensive, provides everything you'll need plus great help, should you need it. it's well worth the cost for amateur installers. the only thing i will caution you on is the dash kit, though it may be fine for you if your stock is a single-din. the dash kit i received with mine (double-din) was a POS that needed way to much modification (it's very hard plastic that's not easy to cut cleanly without proper tools) and didn't offer a slot beneath the HU (just a plastic cover).

12/19/2011 9:56:36 AM

Similar to this one? http://www.crutchfield.com/p_003NDK716/Nissan-Altima-In-dash-Receiver-Kit.html

12/19/2011 10:02:18 AM

that's somewhat similar to the scosche kit I ordered. the one from CF was completely different (it's vehicle/manufacturer specific, for the most part); I believe the CF one for my old truck was more of a generic GM dash kit; the one you linked may fit just fine with no modification. I think CF includes it for free anyways, so I'd recommend going that route first and if it doesn't work, then order one from somewhere else.

[Edited on December 19, 2011 at 10:35 AM. Reason : /]

12/19/2011 10:08:12 AM

Yeah, if you buy the head unit from Crutchfield, they include the dash kit and everything with it. You don't have to order it separately.

The GM kits are pretty generic across the board because it's just a rectangle double-DIN opening, and has been for decades. My 01 Blazer uses the same kit as my parent's 89 and 02 Suburbans and the 86 Oldsmobile that I had in highschool. I'm pretty sure even the newest GM's are still using the double-DIN kit.

12/19/2011 10:26:04 AM

Quote :

"Yeah, if you buy the head unit from Crutchfield, they include the dash kit and everything with it. You don't have to order it separately."

Recommend.

12/19/2011 10:35:19 AM

Awesome, thanks for the help guys. I think the only thing I'll need to research some more is how to crimp wires together and exactly what tools are needed. Can anyone give me some advice on that?

12/19/2011 10:36:50 AM

Solder and heatshrink tubing is best. Next step down is a crimped connector and heatshrink, and finally crimp connector with electrical tape. The only thing you're connecting is the new unit's harness with the adapter harness for your car, so you can put them together anytime then go do the installation later. If you need a hand with it or just want someone to show you, I'll be glad to help you put it together. It shouldn't take more than 15 minutes.

Good article: http://www.mmxpress.com/technical/connections.htm

[Edited on December 19, 2011 at 10:42 AM. Reason : article]

12/19/2011 10:41:40 AM

After crimping wires together, give it a good ol' tug test. If the crimp comes apart you didn't do a good enough job (ie: crimp harder or make sure the end of the wires are where the crimps are). If the wires don't come apart then you did it right.

12/19/2011 10:44:53 AM

If this is his first time soldering something, I'd strongly suggest crimping. It's hard to fuck up a crimp cap.

I've been installing stereos for about 12 years now (3 years professionally) and you will not have a single bit of trouble with a crimp cap.

Another trick of the trade: Use zip ties to bundle the wires together and then zip tie both "sides" of the wires in the crimp cap together. This relieves any pressure from the crimp area itself and will help keep it together even if you tug at the wires.

[Edited on December 19, 2011 at 10:46 AM. Reason : .]

12/19/2011 10:45:08 AM

12/19/2011 10:46:31 AM

I'm sure this is a seriously retarded question...but I assume that ends of the two wires are supposed to overlap in the middle of the connector?

12/19/2011 10:48:10 AM

Yeah, the only reason I prefer soldering over crimped barrels is the size. The solder and heatshrink method makes a compact, neat harness that you can put a small loom around if you need to tighten it up a bit. When I'm doing pretty much any other automotive wiring where I'm not cramped for space, I use regular old crimped barrel joints with heatshrink.

No, they don't really overlap. They meet in the middle and the metal part just gets squashed down onto both wires and completes the circuit.

[Edited on December 19, 2011 at 10:49 AM. Reason : .]

12/19/2011 10:48:23 AM

No offense to the OP here, but if he's asking questions such as "how to crimp wires together and exactly what tools are needed", I'd 1034855% shy away from telling him to attemp to solder two wires together and expect a good clean "hot" joint. Just crimp it and be done with it. Nothing to worry about.

12/19/2011 10:51:07 AM

Good point.

12/19/2011 10:52:30 AM

^^Agreed. I absolutely am not going to attempt to solder, I am a complete noob, as I'm sure you can tell from my questions.

As far as crimping, I assume that crutchfield's instructions will tell me which wires get crimped together? And someone mentioned that not all the wires may be used, what do I do with the extras?

12/19/2011 11:00:29 AM

It may give you a wiring guide, but every head unit is a little different so you may just need to decide what you do and don't need when you're looking at it. They're all color coded, so it's really simple to match up even if you have only a slight idea what you are doing. The leftovers you can simply tape together and leave in the bundle. As long as they're not exposed, it doesn't matter where they go.

12/19/2011 11:18:53 AM

Ah OK, so it really is as simple as them being color coded?

Also, I posted this earlier, but the thread got sidetracked:

Quote :

"I guess the only part I'm still somewhat sketchy on is that when I looked up the harness that I would need on crutchfield, it said that the harness doesn't have a ground wire and that I would have to ground the new radio to the vehicle chassis, no clue what that means really."

[Edited on December 19, 2011 at 11:44 AM. Reason : .]

12/19/2011 11:39:14 AM

It means you find a metal part on the body or anything that's tied to ground and run a wire from that up to the stereo harness. Why that is required, I am not really sure, but it sounds like the factory stereo gets it's ground connection from something that goes away during the installation, so you just run a new one for it.

[Edited on December 19, 2011 at 1:33 PM. Reason : you will probably just need a little crimp-on bullet connector for that so that it can be removed.]

12/19/2011 1:31:47 PM

you will probably just need a little crimp-on bullet connector for that so that it can be removed

Can you elaborate on that? So that what can be removed?

12/19/2011 1:58:35 PM

This is a bullet connector. A sealed spade connector would work as well, this is just a little more compact for wire-wire connections. You can buy them at any auto parts store.
http://www.wiringproducts.com/contents/en-us/d100.html

You have two pieces to put together: a harness that breaks out the vehicle's connector, and a harness that breaks out the head unit connector. The harness for the car side does not have a ground wire and the harness for the HU side does. You will need to bring up a ground from somewhere else on the vehicle, generally anything metal will do. I would make a ground lead with a ring terminal on one end and a bullet connector on the other. The other half of the bullet connector will go on the HU harness' black ground lead. The ring terminal can go to anything grounded, unpainted screws going into metal parts are usually a good bet.

After attaching the ring terminal to something grounded on the car, run the lead back up to where the vehicle's connector is and zip tie it near the OEM plug. Now when you put the HU in the car, you will have the custom harness between the stereo and the vehicle plug, and then that extra black ground wire off of the stereo harness will go and plug into that ground lead that you ran.

12/19/2011 2:27:52 PM

Quote :

""

get the ones that look like this but are actually heat shrinkable.

12/19/2011 4:00:12 PM

^^OK, that makes sense. So this is essentially just a way to connect the lead and the ground wire from the stereo harness while being able to easily disconnect them, right? The bullet connectors from the lead wire and the stereo's ground wire will essentially just "plug-in"?

[Edited on December 19, 2011 at 4:09 PM. Reason : .]

[Edited on December 19, 2011 at 4:09 PM. Reason : .]

12/19/2011 4:08:03 PM

Yes, the two parts will plug into each other. It has a male and a female side.

12/20/2011 7:20:07 AM

Installation was a success! Thanks TWW!

1/3/2012 12:17:38 PM