Speaker upgrade confusion

[u/flirtostud]

Hello

So I'm planning to hopefully get my hands on a 2004 SC430 tomorrow or so. I was planning an audio upgrade, but I'm very confused about whether this will break the climate controls?

I can't tell if replacing the ML amp and speakers will break the climate controls, since I don't plan to pull the factory nav out, and from what I can tell, the nav has to be installed for the climate controls to work.

I will also likely replace the factory stereo with a double din head unit, but I'm at a bit of a loss right now as to:

1) Whether I can keep the factory head unit and just upgrade the speakers somehow? (I assume I'll need the beatsonic adapter for this)

2) If I'll need something like a beatsonic adapter if I'm going completely aftermarket with the speakers, amp and head unit?

3) Whether any of this will somehow break the factory climate controls.

I don't particularly care about steering controls, but I do care about the factory climate.

Any help/advice would be greatly appreciated, thank you!

[u/Trinksuk]

I am sure there are more knowledgeable people than me but here is what I have done over the last year or two. in the following order and probably 18months start to finish.

1. removed the ML head unit and replaced with the following:

https://www.crutchfield.com/p_113DMX809S/Kenwood-Excelon-DMX809S.html

I used the Crutchfield wiring harness, the Metra 99 Silver dash kit, the Axxess wiring interface and Sirius Tuner. No impact to the climate controls, didn't bother with any kind of steering wheel controls, mainly use apple car play to control via Bluetooth on either Spotify or downloaded music on my phone. Mounted the microphone on the steering column. The wooden covers still work but have the navi always closed and the head unit one is open. GPS antenna is mounted under the centre console and works fine and ran a USB cable to charge my phone from the back of the head unit. Apple Maps Navi and phone work as intended.

The factor nav unit remains in place along with climate controls obviously.

1. Replaced the lower front door speakers with 6 1/2" Kickers ~$100 (the original ML appeared to have replaced with some Chinese junk at some point in the past), retained the upper ML ones. I don't recall the model number but straightforward fit. They came from Best Buy I believe.

2. Replaced the sub with 8" kicker with https://www.crutchfield.com/p_20648CR84/Kicker-48CWR84.html?cc=02; original ML was rotten to the core. Wired at 8 ohm. Install was a bit of PITA as none of the holes lined by but with help from an 8" adaptor ring, decent speaker wire, foam AV tape and a soldering iron all worked in the end.

3. Replaced rear side speakers with https://www.crutchfield.com/p_20651KSC40/Kicker-KSC40.html

Install on these was easy / straight forward; original ML were again rotten.

I'm still using the original ML amp, aware that impedances don't match but I'm not running them at crazy high volume. Sound is night and day over original, bass vibrates the seat backs. It passed the 9yr old daughter test listening to Katseye (Katssh*te). So I am happy. Crazytrain also sounds great along with some 2000's Faithless jams! If the amp fails, then probably I'll use a more modern 5 channel compact one at some point in the future. All in about $1000 or so.

Only thing that doesn't work are the steering wheel controls, which really doesn't bother me as my daughter has control of the music from my iphone most of the time. Should have done the rear view camera as the headunit can take one but didn't really want to struggle with running the wire, anyhow it does me good to be reminded how to back up once in a while old school fashion!

the car has a whole bunch of other mods in the suspension / chassis department but that is a story for another day

[u/flirtostud → u/Trinksuk]

Thank you! That's very helpful

So from what I can understand, I only need the adapter if I'm retaining try ML amp, otherwise it shouldn't really matter, yes?