iminslc

I did everything as you described and boom, sound is back to my car, all 4 speakers working, antenna is working. I just have one issue wit the SW, I get power to the socket just once, I connected and power is gone and I don't know what to do after that, wires connected the right way, can I power the SW amp from another source? Besides that I love having sound back to my 1992 SC400, I'm ready to sell it and just need it this thing fixed.

raine

iTrader: (7)

What do you mean you "get power to the socket just once... then it's gone"? If it's gone, check the other end of the wire for 12v.

motorheaddown

The OEM head unit grounds will only work if the stock amplifier is retained. It is the "pass-through" for the head-unit grounds. Additionally, it provides the shielded signal grounds for the low-level inputs to the amplifier and sub-woofer amp. If you bypass the amplifier next to the CD changer, then simply jumper amplifier connector pin B7 to pins A10 and A11 (per Lexus Wiring Diagram), and you'll have OEM grounds going to the head unit.

If the stock amplifier is bypassed but the sub-woofer is retained, then the signal grounds to the sub-woofer are left floating. That's probably not catastrophic, but it never hurts to keep the electrical grounds as designed by the manufacturer.

BTW... great write-up Raine. I have additional contributions I'd like to forward via PM once I'm finished. I'll leave up to you to include them or not. After all, you paved the way with some great content here.

Thanks,
-scott

motorheaddown

Ugh... I hate to make corrections. The ground wiring posted above is absolutely correct; however, the OEM head unit needs to be grounded through the chassis. The ground from the amplifier isn't adequate to power the OEM radio; the outputs still float. Consequently, I would take the safe route and implement the jumper mod above AND ground the head unit to the chassis.

Thanks,
-scott

Neucorp

iTrader: (1)

First, thanks so much to raine. I started with the Metra, experienced a hum with everything off and alternator whine with everything on.

I almost pulled the trigger on the filters, but decided to do it the right way thanks to the great info in this thread. I'll still use part of the 70-8112 so I don't have to mangle the stock harness (A), but be sure to ground it to the body. I'll also be using the AMP+ wire here to trigger the woofer amplifier instead of running it.

I've also bought 2 x 70-1761 harnesses. I'll use part of one for the D1/D5 connection. The other, I'll use on the output harness (F) for the speaker connections. My HU has two sub pre-amp outs. Was going to use a Y into speaker cables and splice positives to D5 and negatives to D1. Is this acceptable? I noticed that you taped off your extra out...

I agree here with ISFFUN. My HU doesn't have an antenna out. I can't logically wrap my brain around why jumpering the ACC and B+ with the AMP+ will make a difference in antenna operation. I don't think I'm going to touch section I unless I have to as the woofer amplifier will be getting its AMP+ from A1 while ACC and B+ are already basically direct to the amplifier. However, I reserve the right to tuck my tail and fall back to the methods described here.

Thanks again, raine!

motorheaddown

I was going to forward this to raine first, but you're asking about the same problem I was working on regarding the antenna.

Apparently, most of the newer head units don't have an "Antenna" output; my pioneer HU is the same way. I still wanted the antenna to function when only running the radio, and the best I could come up with is to use a PAC TR-7 (http://www.pac-audio.com/PACProductD...ons_010505.pdf) as a latched relay (Feature #3). Once programmed, you can use OEM on/off switch to manually raise/lower the antenna since power on/off is already handled by the aftermarket HU. I had to route power to the OEM on/off switch which is used as a momentary input to the TR-7 where it is "latched". Then, you'll simply raise/lower the antenna when you need it using the OEM on/off button, but at least it's not up all the time when the head unit is turned on.

Thanks,
-scott

raine

iTrader: (7)

That wouldn't have worked for me, I turned my OEM volume button into a subwoofer level control **** when I swapped to the aftermarket head unit

motorheaddown

It should still work. The on/off switch is simply a momentary switch that is now disconnected from the OEM head unit; so, it's normally open. With the relay latch enabled through the on/off bottom, I see anywhere from 0 to 20k ohms based on the position of the dial.

You can have your cake and eat it too.

-scott

ProLurker

great write up!

spctre

iTrader: (1)

Is anything other than a Nakamichi amp and head required to convert Pioneer to Nakamichi?

raine

iTrader: (7)

I'll be more specific - no I couldn't, because the only thing left from the OEM volume **** was the ****. I gutted the OEM volume board and mounted the sub level pot into it, then capped it with the OEM **** =)

nicksc4008

Hi I recently changed to a double din and changed my rear speakers to 6.5 my sub n amp don't work anymore I was wondering if I can use my factory sub n amp

raine

iTrader: (7)

Follow directions in post #1.

PseudoK

Nakamichi doesnt have a separate subwoofer amplifier does it.. Probably not possible to use the nakamichi amplifier with an aftermarket head unit..

Naughtlol

Any way of doing this without running the new speakers wires back? Someone way of using the existing wiring? I dont care too much about the sub. But I'm just wanting to get my radio working quickly until I can figure out all the stuff I want to do.(I currently have no headunit cept some $25 amazon special I just got)