DIY installing aftermarket headunit with dash controls in s2000

[3AM]

This is a basic guide on how you can swap out the headunit, to an aftermarket unit and still retain the dash controls.
I chose to upgade the factory tape player and stacker, in my 99 s2000, to a new 2010 pioneer DEH-4250.

Things needed:

New headunit.

Autoleads multistalk adaptor for honda PC99-X61
Autoleads patch lead ( in my case Pioneer)
I was able to find the multistalk adapter with patch lead on ebay, from the UK for around $45 delivered

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lets begin.
as you can see here is my new headunit. and the required Autoleads stalk adaptor and patch lead






When I received the stalk adaptor, I discovered an issue, the plug did not match the head unit.



This was no problem, as the multi stalk adaptor and the included plug with the pioneer, the wiring was the same colours,
it was as simple as cutting and attaching the new plug, simply matching the wire colours.
This was done the proper way, cutting, soldering and heat shrink.

The wires on the multistalk adapter, have printing on them, indicating their use.
so for other brand headunits, make sure you check this against the wiring diagram included in the headunits manual.

There were a couple of wires I did not connect, the power aerial / amp wire, as if i install an amp later, I will use this to turn it on, as far as I know, the s2000 does not need this wire? it only has a little aerial and I didn't notice a radio amp anywhere?
and the illumination from the stock stereo loom, as the pioneer unit does not seem to have a wire for this, or a dimmer function

I looped these wires and heatshrunk them, to ensure that they will not short on anything.



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with that out of the way, we begin to remove the old headunit.
pull firmly on the radio door.
it will pop off easily.





now unplug the factory head unit. there are 3 plugs, the main stereo plug, the cd changer plug and the aerial.



We need to reuse the factory brackets, so undo these from the factory head unit.

when installing to the aftermarket unit, use the screws provided with it. not the factory screws.



Connect the multistalk adapter, aerial and dash remote plug.



fit the new unit into the hole. make sure you dont put undue pressure on the multistalk adapter or the stereo, it may take a few tries of arranging the loom and adapter, to make the stereo fit in easily



after that, reinstall the 4 screws on the stereo brackets and just reinstall the radio door, and you are done.




after thoughts:

Thought I now have dash controls, there are a few things.

Volume works as it should
Mode button changes between aux / radio / ipod etc
the channel button seems to adjust the radio tuning in ipod mode skips songs. I would of liked this to control the station channel, and skip play lists.

the mute button functions but does not do anything, on the multistalk adapter, there is a spare wire to connect to the head units mute input, but pioneer does not seem to have mute function through the stereo loom, only through the IR remote control?
you can here the relay clicking, so the function works,
the reason the relay is there, is aparantly the honda dash controls use 12v for mute, but aftermarket stereos use ground, so this is needed to convert the 12v into ground.

anyways this would work fine with another head unit, with a wired mute input.

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thanks for reading, if you like my DIY please contribute to my PQ (reputation) points!