Lexus Audio, Video, Security & Electronics
Sponsored by:
Old 12-15-14, 01:10 PM
How-Tos on this Topic
Last edit by: IB Advertising
See related guides and technical advice from our community experts:

Browse all: Interior
Print Wikipost

HOW-TO: SC300/SC400 Install Aftermarket Head Unit, OEM Speakers and Sub Working!

Thread Tools
 
Search this Thread
 
Old 04-09-14, 02:32 PM
  #496  
drastiq619
Driver School Candidate
 
drastiq619's Avatar
 
Join Date: Feb 2014
Location: Florida
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
Default

I wired the whole system just the way it was described in the guide and when I turn the key I got nothing so I thought maybe it was a issue with the ground wire so I tried grounding it to the chassis as well as the brown wire and still got nothing. Power light wont even light up. but if I take it inside and wire it to my jump box it turns right on? Wtf fml
Old 04-09-14, 03:54 PM
  #497  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by drastiq619
I wired the whole system just the way it was described in the guide and when I turn the key I got nothing so I thought maybe it was a issue with the ground wire so I tried grounding it to the chassis as well as the brown wire and still got nothing. Power light wont even light up. but if I take it inside and wire it to my jump box it turns right on? Wtf fml
Standard trouble shooting - check fuses, make sure power/ acc / ground is functioning at the head unit plug...
Old 04-09-14, 04:12 PM
  #498  
drastiq619
Driver School Candidate
 
drastiq619's Avatar
 
Join Date: Feb 2014
Location: Florida
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
Default

Well I checked the ground in multiple locations ang got nothing. Not sure how to check for power and acc. Do I need one of those volt meter things
Old 04-09-14, 04:14 PM
  #499  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by drastiq619
Well I checked the ground in multiple locations ang got nothing. Not sure how to check for power and acc. Do I need one of those volt meter things
You can put the ground wire everywhere on the car dude... but if you don't have 12v+ in the first place, nothing will happen.

Yes you need a voltmeter, or even a simple test light will tell you all you need to know.
Old 04-09-14, 04:28 PM
  #500  
drastiq619
Driver School Candidate
 
drastiq619's Avatar
 
Join Date: Feb 2014
Location: Florida
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
Default

Ok so I gotta test power first then ground then acc. Now lets say power is not working can I run some 18g from the battery to the Hu
Old 04-09-14, 04:31 PM
  #501  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by drastiq619
Ok so I gotta test power first then ground then acc. Now lets say power is not working can I run some 18g from the battery to the Hu
You could run that wire just for testing. But I would prefer to find out why there's no 12V+ in the radio harness, since it's supposed to you know - be there.
Old 04-09-14, 04:38 PM
  #502  
drastiq619
Driver School Candidate
 
drastiq619's Avatar
 
Join Date: Feb 2014
Location: Florida
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
Default

Got you. Imma go check the fuses since I dont currently own a voltmeter. I know theres a fuse diagram on here somewhere. Thanks for helping the newbs hopefully ill return victorious
Old 04-20-14, 06:33 AM
  #503  
Waxologist
10th Gear
 
Waxologist's Avatar
 
Join Date: Feb 2013
Location: SC
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

I did mine yesterday. Everything was like Raine said except for A2 on my 98 sc300 was green with a red stripe. I did still turn out to be the correct wire for my dimmer though. Great post!
Old 04-20-14, 06:36 AM
  #504  
Waxologist
10th Gear
 
Waxologist's Avatar
 
Join Date: Feb 2013
Location: SC
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

I also blew the radio fuse under the dash. It was only a 7.5 and my pioneer had a 10 on it so I just changed it to a 10. No problems so far.
Old 04-22-14, 12:58 PM
  #505  
NoKz
Driver School Candidate
 
NoKz's Avatar
 
Join Date: Jan 2014
Location: CA
Posts: 34
Likes: 0
Received 0 Likes on 0 Posts
Default

Just wanted to stop by and said this was an awesome write up! Thanks!
Old 04-23-14, 07:27 PM
  #506  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by NoKz
Just wanted to stop by and said this was an awesome write up! Thanks!
you're welcome dude
Old 04-30-14, 09:49 AM
  #507  
t2d2
Lead Lap
iTrader: (8)
 
t2d2's Avatar
 
Join Date: Apr 2014
Location: Location: Location!
Posts: 4,652
Received 228 Likes on 208 Posts
Default

Thanks for the great write-up! I've been able to solve a few of my problems so far and am working through the rest.

For someone who's setup includes an aftermarket head unit installed by the previous owner, with amp cabling run to the trunk separate from the OEM harness, how would I go about tying that into the power/signal lines in the G-Harness? The info below seems to assume that the tie-in happens at the head unit end of the harness. Which confuses me a bit, because why not just splice G3, G4, and G6 at that end in that case?

Edit: Comparing the 'D' and 'G' harnesses, D1 and G1 match, D2 and G2 match, and D5 and G5 match, but the rest do not. So, I assume the G-Harness (sub amp) has inputs coming from elsewhere that need to be tied into.

Originally Posted by raine
Sub-Amp-Harness (G-Harness):
10-pin plug with 10 wires, 4 on top and 6 on the bottom, as shown below:

Click the image to open in full size.

G-Harness Wire Color Guide
G1 black
G2 red with black stripe and silver dots
G3 blue with white stripe
G4 grey
G5 white
G6 blue with black stripe
G7 brown with silver dots
G8 brown with black stripe and silver dots
G9 black with white stripe and silver dots
G10 red with white stripe and silver dots

Here are the wires in the plug, and where to connect them:

G-Harness Connections
G3 to amp turn-on wire
G4 to amp turn on wire
G6 to amp turn on wire

Last edited by t2d2; 04-30-14 at 09:59 AM.
Old 04-30-14, 12:22 PM
  #508  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by t2d2
Thanks for the great write-up! I've been able to solve a few of my problems so far and am working through the rest.

For someone who's setup includes an aftermarket head unit installed by the previous owner, with amp cabling run to the trunk separate from the OEM harness, how would I go about tying that into the power/signal lines in the G-Harness? The info below seems to assume that the tie-in happens at the head unit end of the harness. Which confuses me a bit, because why not just splice G3, G4, and G6 at that end in that case?

Edit: Comparing the 'D' and 'G' harnesses, D1 and G1 match, D2 and G2 match, and D5 and G5 match, but the rest do not. So, I assume the G-Harness (sub amp) has inputs coming from elsewhere that need to be tied into.
The D-harness connections (Section C) at the head unit were to get the dedicated sub output signal from the aftermarket HU (which is usually an RCA output) to the OEM sub amp using the OEM wiring that's already there up front in the dash where the head unit is.

If there's pre-existing amp/signal cabling to aftermarket amps at the trunk, then you shouldn't have to do the D-harness connections since you'll already have RCAs running to the aftermarket amps already. If your aftermarket amps have a pre-out sub signal I suppose you could splice those directly into the G-harness like you were thinking, but you might still need the RCA to wire adaptor if the aftermarket amp's sub-out is RCA too.

Meanwhile, G harness connections (Section I) are probably still required for the OEM antenna to work only when needed (up with radio, down with anything else).

Old 04-30-14, 12:56 PM
  #509  
t2d2
Lead Lap
iTrader: (8)
 
t2d2's Avatar
 
Join Date: Apr 2014
Location: Location: Location!
Posts: 4,652
Received 228 Likes on 208 Posts
Default

Thanks for the reply. I wasn't clear on an important detail: I have wiring for an aftermarket amp, but the P.O. removed it. I do have two amps in the garage that I thought about using, but I'd rather not eat up the trunk space. If possible, I'd like to stick with the OEM approach as much as possible, using the head unit's (JVC) amplification for the four speakers and the sub's wee little amp. (By the way, anyone know the power rating of the OEM sub and amp?)

I went ahead and tried following your guide after mucking around a bit following my previous post. I opened up the G-Harness and discovered that G3 and G6 were already spliced to G8. Is that normal? (My G8 is solid grey, not brown with black stripe and silver dots.) I connected my pre-amp remote-on wire to that threesome and G4. Next, I cut into the RCA-to-speaker-to-RCA patch cable that connects to the JVC's sub-out and used that to splice into D1 and D5 on the D-Harness.

When I fired it up, nothing happened... I know the sub works, because I tested it with a 9V battery connected to the terminals (produces the staticky pop). I'm thinking I'll need to test the sub amp somehow, either that it's getting power or that it's getting the remote-on signal.

The other thing that could be related is, the JVC's remote-on line was spliced to A1 and A8, as it's used to control all external accessories. (The JVC manual says the remote lead has a 200 mA max.) Those are both the antenna control wires, according to your A-Harness info. Hmm, maybe I'm confused on that matter. In the A-Harness instructions, I figured you were talking about the two mono plugs behind the head unit, one of which provides radio reception, and the other I figured was for raising/lowering it. So, what's the second mono plug for?

I think my rear window has antenna wires added, but I'm not sure. It sure looks like it... And the JVC seems to get good reception with the power antenna down, but I haven't tested it manually raised to see if that makes a difference. Maybe the motor is blown...

Originally Posted by raine
The D-harness connections (Section C) at the head unit were to get the dedicated sub output signal from the aftermarket HU (which is usually an RCA output) to the OEM sub amp using the OEM wiring that's already there up front in the dash where the head unit is.

If there's pre-existing amp/signal cabling to aftermarket amps at the trunk, then you shouldn't have to do the D-harness connections since you'll already have RCAs running to the aftermarket amps already. If your aftermarket amps have a pre-out sub signal I suppose you could splice those directly into the G-harness like you were thinking, but you might still need the RCA to wire adaptor if the aftermarket amp's sub-out is RCA too.

Meanwhile, G harness connections (Section I) are probably still required for the OEM antenna to work only when needed (up with radio, down with anything else).

Old 04-30-14, 01:17 PM
  #510  
raine
Lexus Test Driver
Thread Starter
iTrader: (7)
 
raine's Avatar
 
Join Date: Jun 2006
Location: CA
Posts: 1,515
Likes: 0
Received 16 Likes on 15 Posts
Default

Originally Posted by t2d2
Thanks for the reply. I wasn't clear on an important detail: I have wiring for an aftermarket amp, but the P.O. removed it. I do have two amps in the garage that I thought about using, but I'd rather not eat up the trunk space. If possible, I'd like to stick with the OEM approach as much as possible, using the head unit's (JVC) amplification for the four speakers and the sub's wee little amp. (By the way, anyone know the power rating of the OEM sub and amp?)
I think it's like 40w peak or something rather small for OEM

Originally Posted by t2d2
I went ahead and tried following your guide after mucking around a bit following my previous post. I opened up the G-Harness and discovered that G3 and G6 were already spliced to G8. Is that normal? (My G8 is solid grey, not brown with black stripe and silver dots.) I connected my pre-amp remote-on wire to that threesome and G4. Next, I cut into the RCA-to-speaker-to-RCA patch cable that connects to the JVC's sub-out and used that to splice into D1 and D5 on the D-Harness.

When I fired it up, nothing happened... I know the sub works, because I tested it with a 9V battery connected to the terminals (produces the staticky pop). I'm thinking I'll need to test the sub amp somehow, either that it's getting power or that it's getting the remote-on signal.
My diagram shows G3, G4, G6. Not sure what G8 does though. Maybe that's not supposed to be connected to the others

Originally Posted by t2d2
The other thing that could be related is, the JVC's remote-on line was spliced to A1 and A8, as it's used to control all external accessories. (The JVC manual says the remote lead has a 200 mA max.) Those are both the antenna control wires, according to your A-Harness info. Hmm, maybe I'm confused on that matter. In the A-Harness instructions, I figured you were talking about the two mono plugs behind the head unit, one of which provides radio reception, and the other I figured was for raising/lowering it. So, what's the second mono plug for?
A1, A8 are for getting the motorized antenna to go up or down - nothing to do with actual signal; signal goes to the head unit from those two "mono plugs" (one bigger than the other, right?)... those two mono plugs are connected to diversity system [read below]


Originally Posted by t2d2
I think my rear window has antenna wires added, but I'm not sure. It sure looks like it... And the JVC seems to get good reception with the power antenna down, but I haven't tested it manually raised to see if that makes a difference. Maybe the motor is blown...
OEM is a diversity system with dual antennas - the motorized one at the rear fender and the one built into the rear window; that's why you'll find two signal plugs in the dash instead of one; to use with an aftermarket head unit you would have to get a cheap $5 Y-adaptor that combines the two... and now that I just told you that, i realized that I never mentioned that adaptor for the antennas in the HT LOL

Last edited by raine; 05-10-14 at 10:22 AM.


Quick Reply: HOW-TO: SC300/SC400 Install Aftermarket Head Unit, OEM Speakers and Sub Working!



All times are GMT -7. The time now is 08:31 AM.