1g Eclipse Stereo Question

[StimpsTSI]

My 90 eclipse gsx has 3.5" speakers in the dash, 5.25" in the doors, and 6x9"s in the back. I was wondering if an aftermarket head unit will power all 6 of them, even though most head units are 4 channel. Does the stock dsm wiring have a splice somewhere that puts power to the dash speakers. I am looking into doing my stereo soon, and I dont want to run an amp, so if anyone has any information that would be a great help. Thanks

 

[Quasimondo]

No splice in the harness. Stock 1g wiring has two harnesses on them. One holds power, turn-on lead and the the two dashboard speakers. The other holds the remaining four. If you get a harness adapter, the dashboard speakers remain unwired. If you solder the connections yourself you'll have to splice the dashboard wiring to the front door wiring.

 

[BoostedTalonTS]

That previous post isn't exactly right... The larger plug has all of the power wires and the two front and two rear positive wires on it. The smaller plug has all of the speaker negative wires on it.

The factory door and dash speakers are wired in parallel by the factory... By looking at the factory 1G plug, you can see that the front channels have two wires on each pin. -Your new radio needs to see a 4ohm load on each channel, so if you replace all of the existing speakers, the front channels will read a 2 ohm load with the wiring as it is from the factory (you will notice that the factory front door and dash speakers are not 4 ohms, like the rears are).

Your best bet is to either get yourself a set of efficient (not too power hungry as you said that you do not want to run an amp) separates for the front (install the crossovers just behind the radio location... This way you can cut the radio harness and wire it so that the front dash location will house the tweeters, and the front door location will house the mid range and just simply use the existing wiring*. You will then just wire your new radio to the new crossovers for the front and your new (or existing) speakers in the rear.

IMO, I wouldn't waste your time with buying the after market plug that will mate with the factory radio plug. If you end up replacing any of the front speakers, you will need to modify the factory side of the plug anyways to avoid changing the ohm load.

Also note that both the 1st and 2nd gen T/E/Ls do NOT have a ground wire. The way the factory radios get a ground is from being mounted in those metal brackets. It will also get a slight ground from the antenna's ground connection, but you should plan on wiring up at least a 16 AWG wire to the chassis of the radio and the chassis of the DSM if you are not planning on mounting the radio in those same metal brackets that secure the factory unit(s).

You might think that there is a ground wire, but the only wires in that harness that will show a ground are the ACC wire (until the key is turned on), the illumination wire (until the parking lights are turned on), and the dimmer wire (that shows a percentage of ground, depending on the setting of the rheostat). -ALL of these are NOT GROUNDS! (sorry for yelling, I have seen a lot of others make this mistake before)

Here is a pin out:
(Large Plug): Power
GRN/WHT wire - Illumination
BLK/YEL wire - Dimmer
BLU - 12V+ ACC (Switched)
RED/BLK - Constant 12V+
(Larger Plug): Speaker
YEL/RED - Rear Right spk (+)
*WHT/RED (pair) - One is Front Right dash (+), the other is Front Right Door spk (+)
YEL/BLU - Rear Left spk (+)
*WHT/BLU (pair) - One is Front Left dash (+), the other is Front Left Door spk(+)

Small Plug:
*BLK/RED (Pair): One is Front Right Dash (-), the other is Front Right Door spk (-)
GRY/RED: Rear Right spk (-)
*BLK/BLU (pair): One is Front Left dash (-), the other is Front Left Door spk(-)
GRY/BLU : Rear Left spk (-)

* These are the wires that you want to separate (by cutting them from the factory wire harness). To find what wires go to what speaker, you could use a 9volt battery to test the leads to find what speaker "pops". To determine the speaker pairs/location (since both pairs of the wires are exactly the same colors) just try dirrerent combinations of WHT/RED and BLK/RED for the Rights, and WHT/BLU and BLK/BLU for the Lefts.

Hope this helps...

Oh, and the factory uses a 4" in the front dash location, and a 5.25" if you have a round speaker grilles on your door panel, or a 6.5" if you have a square speaker grilles on the door panel. Also, not all 1st gens came with 6x9s in the rear... Unfortunately, other than deciphering the VIN, there is no quick any easy way to tell what size you have other than removing the panel and finding out.

NOTE:
I am also selling 6.5" factory door speaker inserts (you just swap out these for your 5.25" ones and that allows a 100% bolt-on 6.5" mid in the door, for better mid-bass response.
I also have a set of Eclipse brand (not factory) 6x9s and 1G mounts for sale as well. -PM me if you are interested.