I recently purchased a vehicle that has no stereo installed. The speakers and antenna are there, but no head unit. As far as I know, there is no amplifier, either.

So, I wondered if I couldn't develop a custom wire harness to incorporate my iPhone directly into the speaker system and allow me to charge it and listen to music while I drive.

The car supplies power to a stereo system via 12VDC. There are two circuits on the vehicle's connector that supply 12VDC from the battery and 12VDC from the ignition. To charge my iPhone I will only need one of these, correct? I'm assuming that a charge straight from the battery will be sufficient.

There are 2 12VDC pins in the iphone connector. According to pinouts.ru they are both +12VDC. So I would need to run the 12VDC from the car to these two pins, correct?

Also, the vehicle's connector has one ground circuit. Should I simply tie all of the iphone's ground pins to this single ground?

As far as the audio, the vehicle has no head unit and I'm assuming has no amplifier. Will I need an amplifier?

The vehicle's connector has a separate circuit for each of the four speakers (2 right, 2 left). I'm assuming that I will need to tie both left speakers together and both right speakers together for the iPhone's connector.

Thanks in advance for any help anyone offers. I'm an electronic assembler, but I only have basic knowledge of electronics. I'm pretty confident I can perform the work, I just want to be sure that I won't blow up my iPhone or waste a lot of money doing something that won't work.

A little update on the situation:

"I was afraid that I would need an amp. Ultimately, I just want to tinker and be different. I've also found a couple of other inquiries into doing something similar and thought that I might be able to make these things on the side. There was one guy who wanted an in-dash iPhone dock for his Elise because of space issues.

Also, I really dislike the look of car stereos in general, and I wanted my iPhone to mount into the head unit panel sideways for an ultra-sleek look. Furthermore, it's a theft deterrent. The only thing I want to see when the Iphone isn't in the car is a flat black PVC panel with a iPhone-shaped cutout and a docking connector. It should be as low-profile as possible and be simple.

I'm still pursuing this, I just need to find an amplifier. I'm assuming if I find an amplifier I'll probably have to buy a wire harness that will convert Toyota's connectors (they look a lot like Molex) to ISO connectors for the amp.

As far as charging goes, I've been looking into car battery amplitude ratings to determine if I need to attenuate the 12VDC to protect the phone. I'm also looking into the iPhone's wall-jack plug to find out how apple handles the situation. However, if the amplifier has a 12VDC through-put then I might be able to just go through there and avoid the extra effort. We'll find out.

So far the items and costs are:

iPod/Phone dock connector: $40 (includes "extention board" to make connections easier) iPod/iPhone Dock Connector ordering
Toyota->ISO Harness Adapter: $5-$40 (depending on where I get it)
Amplifier: ???
RCA connectors: $5
Misc power connectors: ???
3/8 PVC sheet, enough to fill the dash and make mounts for the iPhone: $20-40

So far it's looking like $120 just for the stuff I know about. The iPhone connector supplier can build custom cables with connectors if you ask them to. I'm considering doing that to avoid the hassle of soldering to a PCB. It will up the cost, but make installation a breeze. Plus, it would put me one step closer to producing these on a regular basis."

you would have to make the dock connector connect to:

-5v power + and - to charge the iphone (id get one of those car usb things)
-Audio line out
*a relay that is wired to close when the iphone is connected (giving a solid connection to the ignition so you can start the vehicle, you said theft deturent right jk)

to get good sound i would have the audio line out go directly into the amp as if it was coming from a stereo OR have a little preamp that boosts the signal THEN go into the speaker level input of the amp (if applicable)

good lucvk

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Sounds like it would be much cheaper - and easier - just to install a car stereo and use an FM transmitter, or get one with a iPod jack.... Oh, and you could then get one of the hundreds of car mounts for your iPhone....

Plus, then you could use your car stereo as a car stereo too.

have you ordered anything from the ridax company yet? I am looking into making a custom harness as well, but will provide video out to my navigation screen and need some parts that they sell on ridax.. I tried contacting them, but they do not pick up the phone or reply to my emails..