full stereo install

Well the dash is out so it's time to get the stereo all wired up, no excuses.

I have collected the components below:



head unit: https://www.sonicelectronix.com/item_68934_Alpine-CDE-143BT.html RMS/Peak = 18/50 x 4 channels
powered sub https://www.crutchfield.com/p_777B8PTD/Sound-Ordnance-B-8PTD.html
rear speakers https://www.crutchfield.com/p_500SPS619/Alpine-SPS-619.html RMS/Peak = 85/250
front speaker http://www.ebay.com/itm/-/360719700022? RMS/Peak = 60/100 per channel on 2 channels.

Just last week I won at auction two Soundstream Picasso P2.200 (2 channels X 100 watts) if I need or want to use them. I also have some good lengths of 10 gauge wire and an inline 30amp fuse for it, and an 8 gauge subwoofer setup kit with a fuse if I prefer to use that.



My plans are vague. My basic goal is to have something that sounds decent but won't shout "steal me" to anyone who glances in the car. I was thinking of putting the sub under the passenger seat (but will that make passengers uncomfortable?), building two boxes for the alpine speakers to go under the back window tray, maybe attach them using nutserts in the hollow segment of the back wall there under the window (but will that lead to vibrations and leakage at the window?). I've made it this far in life without really understanding ohms and watts ratings and such for music, but I guess that will have to change a little bit as I figure out if I need an amp for the rear speakers.

The immediate goal is to wire for the sub and head unit from the battery. It seems most people suggest wiring right to the battery rather than going through the fuse box. Will I need a separate wire for head and sub (and amp if I do that?) or can I put them together. I assume I need some kind of junction box or some way to protect the fuses down by the battery? Will I need relays down there with the fuses? The sub install directions suggest running the power wire and music signal wire on different sides of the car to avoid alternator whine. Should I go in the plastic wire guides on the side or just somewhere under the carpet? My carpet is pretty loose and is on the agenda for a change out but that's another issue.

If you go with relays for the heavy gauge wire, they are available locally at Advance Auto etc, like 40 amp capacity etc.
I rewired my headlights with relays, to by-pass the small wiring the factory used, and they are sure brighter now, so relays do carry higher current better....

10 gauge wire will carry quite a bit of current, but 8 gauge would be better, depending on how long the run of the wire is...
Your alternator may need to be up-graded ! ! Get a list of the current that all the components draw, as well as all the electrical etc in the car and go from there for alternator and wire size capacity.. The safe way, is if everything in the car when on, is 80% of the alternator capacity, you will be OK...

I would first look at the diagrams supplied with the components to determine the best source of power. I suspect the head unit would be good with switched main power from the fuse box, and constant power for the memory functions.

The sub/amp depends on how it is turned on. You could run a power wire to the rear and terminate with a junction block, and also a switched power wire to a separate junction block. Then wire up the components as directed by the manufacturer.

I'm looking at the electrical diagrams in Chilton and there's no indication of what current everything in the car draws. I'm studying the instructions in all the component boxes to figure out a basic diagram. It hadn't occurred to me that I might need a bigger alternator but I guess I should check before I start splicing up wires.

My 73 parts car has footwell courtesy lights but my 75 does not, only the dome light. I guess I might as well try to add the footwell lights while I'm doing all this wiring. I hate to hack up the harness just for some courtesy lights. I think the 73 ones are the same as my S10 so this could call for a junkyard visit.

Looks like I'm going to try it without the amp for a while. I still need to run an 8 gauge wire from the battery to the powered sub. I have a solenoid setup for the starter. Can I safely run the amp power wire from the live side of the solenoid? I could put the fuse right next to it on the fender well. If not, what is the conventional way to connect this wire to the positive battery terminal?

That would be a good place to source battery voltage. I like your plan of having the fuse close by to prevent a dangerous short in the event the wire insulation is compromised.

There are as many ways to connect to battery voltage as there are opinions on how/why to do so. It kind of depends on how "clean" you want it to look.

One of the things to consider in addition to a higher amp alternator is the gauge of the wire that recharges the battery. If you run an amp that draws a lot of current, and have an alternator that can keep up with the demand, the factory harness can be a bottleneck. You can overlay with extra wire, just make sure you have fusible link or fuse that is appropriate for the app.

You could probably get by with just an upgraded alternator if the stereo is all the electronics you are going to add, but if you are going to go with fuel injection, for instance, I would suggest upgrading the size of the supply side in the harness.