dual deck install

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=25229
Printed Date: July 16, 2025 at 8:36 AM

Topic: dual deck install

Posted By: HeathMac
Subject: dual deck install
Date Posted: January 24, 2004 at 10:11 PM

does anyone have a diagram for how to wire a two deck system that uses the same speakers and the same powers and shuts off when the other deck is turned off? i had this diagram at the last shop i worked at but lost it ( damn me!)

any help would be wonderful

Replies:

Posted By: moody
Date Posted: January 24, 2004 at 11:37 PM

HeathMac wrote:

does anyone have a diagram for how to wire a two deck system that uses the same speakers and the same powers and shuts off when the other deck is turned off? i had this diagram at the last shop i worked at but lost it ( damn me!)

any help would be wonderful

you should be able to just install a multi-pole switch that disconnects the speakers from one amp and connects them to another. Shouldn't hurt the amps to continue running into infinate loads. Then just split the power two ways and have both decks on all the time?

Posted By: jimmeezgolfvr6
Date Posted: January 25, 2004 at 2:43 AM

for each speaker output wire from each head unit, you will need to use a spdt relay in a 5-wire configuration.....87 being the speaker output from one h/u, and 87a being the speaker output from the other one. 30 = wire going towards speaker. 86 = remote turn-on ouptut from the same h/u as 87. 85 = ground.

you will need a total of 8 relays with this method if you have head units that have 4 pairs of speaker outputs. use one more relay if you want one h/u to turn off when the other turns on. both h/u's must have remote turn-on outputs.

to save space and relay costs (depending on how cheap you can get spdt relays for), you can go to radio shack or any other electronics store and get 2 of these relays that will do the same thing:
https://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F013%5F000&product%5fid=275%2D214

Posted By: HeathMac
Date Posted: January 25, 2004 at 2:45 AM

what im looking for is to run an aftermarket deck and an oe deck with both decks working the same speakers

Posted By: RufNUSD
Date Posted: January 25, 2004 at 9:23 PM

Uh well it was just explained to you what to do. They make a small relay setup as Jimmee described. It requires good soldering skills as the leads are very small and compact.

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Someone pass me that bottle.

Posted By: HeathMac
Date Posted: January 26, 2004 at 4:33 AM

uhm my reply dident post till after the second guy replyed. im sooo sorry to bother you and your big brain sorry please forgive me for my stupidity