Head Unit constantly on?

[ReportDevin]

So I bought a new car and I knew about some of the interior problems, like the head unit constantly being on. So I decided today to get behind the dash and check out the wiring and by god this is a mess. I don't know where to start and I don't have a wiring diagram.

But the HU is constantly on, and so to turn it off I just take the faceplate off. But is there anywhere to start to find out why it's constantly getting power? Any help would be appreciated.

[SkarredSierra]

Is it wired with an adapter that plugs into the factory harness or did they splice into the wiring?

[Pioneerchuck]

Whoever did the install more than likely has it wired to a 12v constant instead of a switched on/off source. People who dont know any better will run the 12v (+) constant and the 12v (+) switch or ignition wire to a "hot at all times" source and this is where you get a head unit that stays on 24/7. Best bet is to clean out whatever they've done, bring the harness back to stock, then start fresh.

[ReportDevin]

12v constant sounds like what might be going on. It's a jumble of wires all twisted together with end caps so I'll go in tomorrow morning and try and mess with it. Busy under the hood right tonight.

Now that I look at the picture it doesn't seem tooo bad. But it bugs me when half the wires are red.

[SnowDrifter]

That's giving me a brain bleed looking at it

It's been a minute since I've put a head unit in... Look as close to the radio as you can, IIRC there should be a solid yellow and a solid red wire. Solid yellow is constant 12v battery power. Solid red is switched - power when ignition is on, dead when ignition is off. Check the red one with a multi meter and make sure it doesn't have any wire strands or something lame sticking out making contact with anything else.

What's year/make/model of both car and radio? I'll see if I can find any wiring diagrams for the factory so we can start making sense of all this

[ReportDevin]

That's giving me a brain bleed looking at it

It's been a minute since I've put a head unit in... Look as close to the radio as you can, IIRC there should be a solid yellow and a solid red wire. Solid yellow is constant 12v battery power. Solid red is switched - power when ignition is on, dead when ignition is off. Check the red one with a multi meter and make sure it doesn't have any wire strands or something lame sticking out making contact with anything else.

What's year/make/model of both car and radio? I'll see if I can find any wiring diagrams for the factory so we can start making sense of all this

1994 Honda Civic Del Sol - Pioneer DEH-X16UB

[SnowDrifter]

For the wiring coming out of your car:

And for the radio, what I'd do is go on eBay and buy a plug for pioneer head units. From there you can connect the wires that go to the head unit to the corresponding wires coming out of your vehicle.

I hate dealing with this garbage because someone was too cheap to buy a $4.99 connector

[ReportDevin]

So according to that diagram, ACC and Constant Power aren't even connected. I'll have to figure all this out later I don't want a headache right now. Thanks for the help Snow

[Pioneerchuck]

the plug for the radio doesn't seem to be the part you'll need. From the looks of it, they cut off the factory plug and wired directly to the factory wiring. This is what happens when someone doesnt want to pay the $10 for an adapter. You will need to obtain the factory side harness connector. As well as the adapter connector. I have both of them listed below.

This is the factory side connector. This is what you should see when you pull the radio out of the vehicle.

https://www.amazon.com/Metra-71-1720-Reverse-1986-1998-Vehicles/dp/B0002BG6AA/ref=pd_lpo_263_tr_t_2?ie=UTF8&refRID=BEGDQV7ZVQ74SV3PGR8W

This is going to be the adapter you'll need to go from that plug ^^^ to the wiring on your new headunit.

https://www.amazon.com/Stereo-Harness-Honda-wiring-installation/dp/B000KL115W

All in all you'll be looking at maybe $20 after shipping to do it right. So once you have those connectors, you can follow Snow's wiring diagram that he provided for you and you should have it looking factory and nice and clean in about 20 minutes.

[Rich Schenk]

I agree looks like they hacked the crap out of your factory harness. First thing I would do buy new factory harness and ditch those wire nuts. Looks like a fire hazard. Get new hu harness too solder and heat shrink everything the way it's supposed to be and you should be good if you still have a issue with acc run a new wire from ignition harness just fuse the the wire.