aftermarket radio question

[Brightyellow69rtse]

ok when i got the car many years ago someone totally hacked up the harness to wire the radio. it was wired wrong and totally forgot what it was doing when you shut the key off. i have since put in all new harnesses. im entertaining putting in a aftermarket cd player but i really dont want to hack up the harness.  im really hoping theres an adaptor but i seriously doubt it.  if not does anyone  know what wires i need to tap into?

[RECHRGD]

You could just grab unswitched power from the fuse block, see the FSM wiring diagram.  Most people disconnect the battery on these old beasts when not in use anyway.  So if your of the same mindset, then the radio will loose its mind anyway.....

[flyinlow]

My alpine need four wires + speaker wires.

1 . main power wire from the ignition switch accessory feed.
2. battery power for the memory
3. dimmer wiring (tapped into the light in the ash tray) this signals modern radios to dim the display when the lights are on.
4. ground. frame of the radio is sometimes grounded also

You can combine 1&2 to a battery feed if you always turn the radio off..........can you say jumper cables?

[MaximRecoil]

You don't need to hack into the harness, just add new wires. You can tap into the fuse block. If I remember right, on the back of the fuse block there are tabs for quick disconnect terminals. There may be extra ones that aren't used, or you may be able to use one that is already being used by putting a "piggyback" terminal (link) on the end of your new wire(s), then plugging the original wire(s) from the harness onto the piggyback tabs.

For your aftermarket head unit, you need:

- A constantly hot 12V source for the memory (or don't bother if you don't care if the radio "remembers" anything like radio station presets, the time, etc., after you turn the car off).

- A switched 12V source (only hot when the ignition switch is on or in the accessory position). This is the power source for your head unit.

- Ground. Easiest thing to do is find a factory hole in something that is part of the car's chassis behind the dash, clean the area around it to bare metal, and screw or bolt your head unit's ground wire there (crimp a ring terminal on it of course).

- Antenna. Your factory antenna's plug will most likely fit into the antenna port on the head unit as-is. If not, there are adapters you can buy.

The rest is a matter of hooking up the speakers. When I installed an aftermarket stereo system in my car, it didn't have any speakers in it at all, but it originally came with the optional 3 speaker setup on the dash top (5 speakers total). This made it convenient. I just ignored the center speaker location, and found a pair of aftermarket speakers that fit into the left and right dash speaker locations, and a pair that fit into the rear speaker locations, and wired them to the head unit. I used a 12-terminal standard .093" Molex connector for all the wires; i.e., 8 speaker wires plus 3 power/ground wires so that I could easily connect and disconnect the head unit, and to make things neat/tidy.

If you have the standard 3 speaker setup (one center speaker in the dash top, two in the rear), there is no ideal method of hooking up a modern head unit using the factory speakers or factory speaker locations. You can of course just hook up one front channel from your head unit to a single speaker in the front, but you won't have stereo up front obviously, and one of your front channels is going to waste. Some songs make use of stereo recording in such a way that they will go silent in parts if you only have one channel hooked up. Your stereo back speakers wouldn't go silent on such songs, but it would still sound weird up front.

Some people have made an adapter plate that fits in the front center speaker location, and accepts two small speakers. This would be better, but it is still not ideal, as you won't get any perception of stereo separation with both speakers so close close together in the center of the dash, but at least you'd always hear the whole song, and none of your head unit's channels would be going to waste.

[Brightyellow69rtse]

good info thanks guys. i havent been disconnecting the battery since i did the all new wiring.

the car has the one 4x10 in the center of the dash. it has 6x9s in the rear.  someone hacked up the doors to put in 4x6's in there. ive since replaced the door panels and really dont want to put speakers in the door.   i may just hook up the 2 rears for now at least.  im sure the one in the dash is toasted    last i checked jensen was the only brand who made a 4x10 anyway.

my work is a alpine dealer and i can get things for cost. i would like something with bluetooth so i can just feed it from my phone. 

[MaximRecoil]

Lots of companies make 4 x 10 speakers: Pioneer, Kenwood, Kicker, and others.

The only thing you can do to make a 3 speaker setup work properly is to add an external amplifier to the system. With an external amplifier, you can sum the front two channels into a mono channel (no missing parts of the music in that case, but of course, no stereo separation in the front).

There's more than one way to do this, and ideally you should have a head unit with two pairs of pre-outs (most inexpensive aftermarket head units only have one pair).

1. A 4-channel amplifier. Run RCA cables from both sets of your head unit's pre-outs to the amplifier. Run speaker wires from the rear two channels of the amplifier to the rear speakers as normal. Bridge the front two channels of the amplifier for your front speaker.

2. A 2-channel amplifer. Run the front pre-outs to the amplifier; bridge the amplifier mono; run speaker wires from it to your front speaker. Use the rear two channels of your head unit's internal amplifier to power the rear speakers.

Both of those options will allow your head unit's front-to-rear fade to work properly. If your head unit only has one set of pre-outs, it could work, but the front-to-rear fade function would work in reverse (because head units with only a single set of pre-outs assign it to the rear by default, while you would be using it for the front).

Personally, if I were doing it, I would get the smallest and cheapest bridgeable 2-channel amplifier I could find (the option I described in #2). Also, go easy with the gain and/or fader and/or volume knob, because even an el cheapo low powered external amplifier will be capable of putting out way more power in bridged mode than any 4x10 coaxial speaker wants.

[66chargeragain]

There are a few companies making a "stereo" 4 x 10 speaker, it has two tweeters and you connect both front channels to it as it has a right and left channel input. I have one from Custom Autosound and it sounds great along with my rear 6x9's. About $75.00, no need to cut dash or door panels. I did try mine before hooking up the rears and even by itself sounded decent for those who want stereo and don't want to cut holes for other speakers.

[MaximRecoil]

There are a few companies making a "stereo" 4 x 10 speaker, it has two tweeters and you connect both front channels to it as it has a right and left channel input. I have one from Custom Autosound and it sounds great along with my rear 6x9's. About $75.00, no need to cut dash or door panels. I did try mine before hooking up the rears and even by itself sounded decent for those who want stereo and don't want to cut holes for other speakers.

A dual voice coil ("DVC") 4 x 10; I didn't know anyone made such a thing. DVCs are usually subwoofers, and their purpose is to give more wiring options (i.e., a subwoofer with two 4 ohm voice coils can be wired as an 8 ohm subwoofer or a 2 ohm subwoofer, depending on whether you wire the voice coils in series or in parallel), rather than getting stereo from one speaker. Subwoofers are nearly always fed a mono signal, regardless of how many of them you have, and/or how many voice coils you have.

But yeah, a 4 x 10 DVC would be the easiest option, and you would get true stereo from it, albeit with no sense of stereo separation due to both channels sharing a single woofer cone, and with the two tweeters being so close together. The shared woofer cone is actually an advantage over making a 4 x 10 adapter plate to hold two small round speakers close together, because you get more cone area with a single 4 x 10 cone than with two round cones that would fit on a single 4 x 10 adapter plate.