AUX switched source input via relay
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=25849
Printed Date: July 05, 2025 at 5:48 AM
Topic: AUX switched source input via relay
Posted By: eMass
Subject: AUX switched source input via relay
Date Posted: February 04, 2004 at 3:57 PM
Hi,
Need some advice/help...
I have a Lexus RX300 that is in need of an AUX jack for my iPod. It
has a proprietary audio system which I need to keep intact. I've
looked at a number of aftermarket AUX adapters from companies like
PAC, Blitzsafe, PIE, but these are a lot of money and and seem overly
complicated for such a simple thing.
My idea is to run the factory +/- CD changer signal outputs to a relay
that is also wired up to the +/- leads going to a female stereo aux
jack.
I have a number of questions about this...
1. Will this even work?
2. What kind of relay do I need (I assume double pole double throw)?
3. Does the relay have to be a special audio signal type of relay?
4. Will the relay automatically switch (and stay switched) whenever
the iPod offers a signal?
5. Do I need a mechanical A/B switch also?
6. Will I hear a noise "pop" when switching? If so, how do I avoid
that?
Any help would be greatly appreciated. I've talked with a number of
installers in the area who seem clueless about relays (go figure) so I
guess I'm on my own to do this. =(
Best,
D. ------------- ->eMass
Replies:
Posted By: DYohn
Date Posted: February 04, 2004 at 7:26 PM
Bad idea. Use the PIE input adapter. Trust me, you will create a nightmare trying to do it yourself.
Posted By: geepherder
Date Posted: February 04, 2004 at 8:18 PM
Yeah, I'd say get the adapter as well. An FM modulator will work as well, although not as clean. I used to work with a guy that would dream up stuff like what you mentioned. Not his fault- he kinda had to since the sales people were notorious for overpromising (I'm sure noone else here has had to deal with that  ). Anyways, he'd wire the two negatives together, and put the positives on a toggle switch to change from one source to another- in essence building an A/B switcher. I definitely would not recommend this, that's just what was done. Yes, it's quite possible you'd get a pop. ------------- My ex once told me I have a perfect face for radio.
Posted By: eMass
Date Posted: February 05, 2004 at 7:17 AM
I get that you folks think it's a bad idea but nobody has given me any sort of technical reason why it's such a bad idea. If it's just because it sounds too complicated or you're not familiar with electronics then please don't opinionate. I'm simply looking into whether or not this will work and if there's any technical reason I shouldn't do this as opposed to spending $100+ on a PIE setup. It just seems ridiculous to me to spend that kind of money on a glorified AUX jack if the same unit can be built for less than $10 and a bit of know how.
-------------
->eMass
Posted By: DYohn
Date Posted: February 05, 2004 at 10:56 AM
A simple mechanical relay will not be sufficient. It will add signicant noise. You will have to cut into the car's wiring harness to find the wires you need to switch. After-market adapters are designed to match the input impedence expected by the head unit. Not only that, it will have the proper connecters to plug and play into your vehicle without modifying the existing wiring and will present the head with the proper signal so that it thinks the additional input is a second CD changer. It is not all about nuts and bolts wiring. The proper adapter can be had for well under $100. And by the way, I do not opinionate in areas I am unfamiliar with. Thanks.
Posted By: the Finn
Date Posted: February 05, 2004 at 11:14 AM
One of the head guys at my shop does it the same way you are talking about, without the PIE piece. He does it because he trusts his own work more than that of the manufacturer. It is more expensive, however, and I would not attempt it yourself unless you are very familiar with exactly what you are doing. If this is a DIY, get the adaptor, it will save a lot of headache.
-------------
~Cory
Car Concepts SLC
Alpine F#1Status Certified
Posted By: eMass
Date Posted: February 05, 2004 at 11:49 AM
DYohn] wrote:
he proper adapter can be had for well under $100.
Great! Can you tell me where I can pick one up? Thanks. ------------- ->eMass
Posted By: eMass
Date Posted: February 05, 2004 at 11:50 AM
the Finn wrote:
One of the head guys at my shop does it the same way you are talking about....It is more expensive
How come it's more expensive? Because of the labor? ------------- ->eMass
Posted By: DYohn
Date Posted: February 05, 2004 at 12:07 PM
This one should work for the Lexus, or they can tell you which will. https://store.yahoo.com/logjam/pietoyaux.html
Posted By: eMass
Date Posted: February 05, 2004 at 6:16 PM
DYohn] wrote:
p>This one should work for the Lexus, or they can tell you which will.https://store.yahoo.com/logjam/pietoyaux.html
Thank you.  ------------- ->eMass
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