Hey, does anybody know what this little button’s function is? I’ve looked all over and can’t find a reasonable explanation to its existence. Is it something the previous owner put in or stock? It doesn’t seem to do all that much when I press it. If it helps, my car is a 1993 sc400. Thanks in advance!

 

definitely aftermarket. Could be a relay switch for an aux input that was wired in or a number of other things. If you don't want to press it and find out, you can take the panels off and trace the wires.

 

^^ Seconding. It is a nicely placed but definitely aftermarket switch. There is no way to know what it does unless you flip it or trace the wires.

Something practical that it *could* be is an antenna-up limiting switch since that is very easy to make but putting the switch in-line on a specific wire on the stereo harness. But it could be anything.

 

To third what others said, factory controls are never generic like that.

 

That’s what I thought, one day when I have time I’ll have to trace the wires. Thank you!

 

Ejection seat 😂

 

 

"Ejecto seato cuuhz!"
-Tyrese 2F2F

 

Thinking aftermarket seat heater. Turn it on & see if your butt gets hot.

 

Weirdly enough I just found out what it was and it's really boring. It simply allows me to turn my head unit dimmer on or off. Like it blocks the option to switch the display brightness when it's off. No clue why the previous owner did this, but glad I figured it out. An ejecto seat would be much cooler...

 

Glad you finally found out what it does!

I have a generic switch exactly like that which I place just above the fold-out cupholder assembly on the center console. I made that my motorized antenna up/down switch since with aftermarket head units the function of making the radio antenna go down when the AM/FM radio mode is not engaged or if the entire head unit is off does not work any more the way it does with a factory head unit. There is a slightly smaller than normal version of the switch that I used in order to perfectly and cleanly fit in that area.

 

If I have some extra time, I absolutely want to wire up a switch to my antenna. Any tips?

 

I haven't done it in a while but I have my diagrams somewhere. I have had so many things getting in the way of SC projects I only got it half wired so as to be an "antenna raise limiter switch" on startup with the switch set to the "OFF" position.

That's pretty easy to do. The harder part involves some additional wiring that needs to run from your head unit area all the way under the center console up to the wiring harness under the rear windscreen package tray where the Pioneer factory amp is located. I got to the point of finishing a plug and play wiring harness for this but I haven't installed it yet on my SC.

Raine covered the wiring for this in his overall thread for aftermarket head units. The specifics are buried in those pages but they are there.

The thing is that the easiest method limits the antenna from raising at startup. As soon as you flip the switch to complete the circuit the antenna raises... but it won't go down again until you shut the car off. You can flip the switch to "off" wired as a simple circuit interrupter while the car is running but the antenna won't go down until the engine is shut off.

Now the more tedious part that I mentioned above... that done in addition to the easy first part is what will make the antenna go up with the switch set to "ON" and down with the switch set to "OFF" with the vehicle running.

Here are Raine's threads, one of which contains the relevant wiring at both the head unit area and the back under the package tray where the amp is located. Nakamichi equipped cars may work differently with his method-- I don't know. I am not sure that Raine specifically mentions adding a switch but once you see the circuit, if he doesn't (it has been a while since I read his notes) it makes sense why someone would add one.

https://www.clublexus.com/forums/lex...ead-units.html

https://www.clublexus.com/forums/sc-...rom-raine.html

https://www.clublexus.com/forums/lex...b-working.html

....

As for the switch that I used, I ordered a bulk pack off Amazon which were generic round black ones with no indicator light. I don't recall the size but it's a very common one and a pack of quite a few was dirt cheap. I measured its diameter and sized up a little hole saw just a bit smaller than was needed and as I recall I then carefully, patiently made the hole a little larger a bit at a time until that switch fit in without forcing it too much and without it being loose. Take your time since these OEM interior bezels are't always easy to find replacements for.

It needs to be a small generic switch smaller in diameter than the one you found under your steering column in order for it to fit into the same location I used (right above the fold-out cupholder).

Hope this helps! : )

 

When the Pioneer head unit got installed, the antenna would engage. I rarely used the radio so had the shop install a rocker switch similar to the one you show under your steering column. Mine ended up in the ash tray. Antenna is always down unless the switch is on. Highly recommended….

 

Yep! Exactly! This is the easiest method: to simply interrupt one circuit connection so as to keep the antenna from going up *until* you want it to.

But without the more involved second part involving some wiring changes to the Pioneer amp connection directly to the head unit area it won't make the antenna go down again while the car is on. That happens automatically when you shut the car off.

I was one of those who bought and installed the now discontinued Beat Sonic SLA-10B adapter to make installing an aftermarket head unit easier. I was frustrated to learn that even with that installed the antenna would always go up when you turn the car on and it would only go down when you turn the car off. So the simple antenna limiting switch installation was a mandatory addition.

I actually escalated questions about this through Beat Sonic's customer service and got them to put me through to one of their electronics engineers based at their home office in Japan who was familiar with that stereo adapter design for Soarers (which is 100% compatible with SC's).

He more or less confirmed that when they designed it they understood the factory antenna would do this on U.S. models but since the Z30 Soarers never got a motorized antenna at the rear they never designed any extra consideration in for the U.S. and Canadian SC's with their SLA-10B adapter since it was a mostly Japan market stereo adapter which just so happened to also be 100% compatible with the SC... other than leaving that one annoyance unaddressed.

So it was marketed for both versions of the car with that one caveat for SC owners if they intended to keep their factory motorized antennas (which still get really good reception IMO).

When I detailed Raine's wiring pinout changes intended to address this the Japan-based Beat-Sonic engineer seemed to think it would work (in other words not just the simple antenna limiting switch which he also suggested independently but also Raine's further changes which would allow the antenna to be manually controlled for full up and down choices while the SC is on).