The second generation IS250 that come equipped with auto-folding mirrors do not allow for folding the mirrors once ignition is turned off. This is because the switch is wired via the ACC +12v supply going to the mirror motor.

Power folding mirror motors regardless of brand all work in similar way. They have two wires going to the motor. It folds and unfolds based on the polarity of the power supplied to it. The internal switch that folds the mirror basically flips the ACC +12v and ground around going to the 2 wires of the mirror motor. I initially did some testing and was able to operate the mirrors independently using +12v

I was going to build my own polarity switching relay circuit but then came across these readily available "Intelligent Universal Auto-Folding Mirror Systems". for sale on eBay for as little as £5 from Chinese sellers. I purchased mine for £6.49 as that was the cheapest seller that had UK/EU stock which came in a few days. £5 one would have taken 20-30 days to arrive from china which wasn't a great option for the price difference. The price of buying components and project box etc and making my own unit would have cost me more than £6.49. This system is universal and works on the same principal. As long as it's wired correctly, I had no doubt it would work. 

With this system installed, the internal mirror folding switch still works just like normal. The module is marketed as being an intelligent folding system. This is because if you fold your mirrors using the internal switch and then turn off the car, the system will not do anything when you lock or unlock the car. It's because let’s say you parked in a really tight spot where you had to fold your mirrors with the switch, and then if the system just unfolded it when you unlocked it, that would be a disaster. So the system doesn't operate if you manually fold the mirror with the switch before turning ignition off. If you leave mirrors normally unfolded and turn off ignition then system operates normally.

The system works great. Below is a video demonstration of the system working followed by my guide on how to install the system on a second generation Lexus IS250. You can follow the installation guide to a certain extent to install on any car as long as you can find the equivalent cables to tap into on your car.



You can buy the universal mirror folding module from many different sellers on eBay. I think there are two or three different variations manufactured by different companies. But the one I bought looks like the following pics. My install guide is based on this module and so the colours will match this module. The other systems should work too, but you will need to match up the equivalent wires.







IMPORTANT NOTE FOR LHD CARS
These instructions are made for a RHD IS250. I have tried to provide the possible solutions in my diagrams. But please always check the connections to make sure they are what they are supposed to be.


DISCLAIMER:
Use this guide at your own risk! modifications to any electronic systems that are not done correctly can pose a huge risk (including and not limited to car fire). Therefore, if you are not confident in electronics please do NOT attempt it. I accept no responsibility for any damage to your vehicle or personal injury as a result of following any guides. 


TOOLS NEEDED:

  1. Preferably a soldering iron for a clean installation
  2. Heat gun to shrink the heat-shrink tube over solder joints. (A lighter will work if you are careful, a hair dryer may also work).
  3. Wire cutter and strippers
  4. Phillips screwdriver to remove the screws for the door card.

MATERIALS NEEDED:

  1. The universal mirror module itself
  2. Solder wire to solder the joints with the soldering iron
  3. Some insulation tape to tidy up and have a clean install
  4. Some heat-shrinking tube. I will explain about the heat-shrinking tube next

HEAT-SHRINK AND WIRE JOINING INFORMATION:

If you've not done heat-shrinking before, please watch some YouTube videos on soldering and heat-shrinking. It gives you a clean and tidy joint with less risk of exposed wires. If you are not that bothered about a clean and safe joint then you could use insulation tape to wrap the joint but if you do this please make sure your joints are properly insulated. For straight 1 wire to 1 wire joints I used a 3:1 glue-lined heat shrink with 2.4mm internal unshrunk diameter. There are two wires going from the switch connector to the mirror motors, these two will need to be cut and then routed through the universal module. Once you cut these two wires you are then left with 4 open-ends of wires. These 4 open-end wires will go to 4 different wires on the universal module. These 4 joints will be the only straight 1-to-1 joints. The remaining 5 wires on the module will tap into existing lines. To tap into existing lines, you have a few options.


  • Option 1: Use wire tap-in crimps like the one pictured below:
    • Watch some YouTube videos on how these work. One problem with these sometimes is that you can make a connection and press the crimp down but sometimes it just doesn’t pierce the wire sleeve enough to make a contact. So if the contact isn't made you will be left wondering why things aren’t working. If you are using these, I would recommend just helping the contact by shaving the wire sleeve a very little amount where the crimp will go before you crimp it. This way when you press the crimp down, it doesn't have to work too hard on piercing the wire sleeve and will make contact for sure. This is probably the easiest method but can be quite bulky as you will have so may of them around. A good tip is also to make sure you wrap the with insulation tape too just to be safe.
  • Option 2: Solder joint and heat shrink. This is the method I prefer and use. If you do a T joint with solder then you cannot really put heat shrink over it as you don't have an open-end wire for the heat shrink tube to go in. So with a T joint you will have to use insulation tape. Because I like a clean install, I cut the wire and I used 4:1 glue-lined heat shrink sleeve with 6mm internal diameter. Please watch YouTube videos and familiarize yourself with these techniques if you want to do this. My joints look like the picture below:

IMPORTANT NOTES BEFORE WE BEGIN: 

  1. You must have motorised mirrors with an internal folding switch for this mod. This module won't magically make a non-motorised mirror fold 😂
  2. If you live in a region where your mirror housing freezes up during winter seasons then please take precautions during the freezing mornings where you think the mirror housing might be frozen. If enough ice builds-up around the mirror swivel point then the motor cannot operate and can potentially blow a fuse. 
  3. I will reference colour code of the cables from my 2006 car. However, from what i've read, Lexus have different connector configurations with different colour codes for different region and variants of the car. I have tried my best to cover all the variants I am aware of. However, if the connectors don't match the ones in my installation illustration picture then please find the matching wire as per the description. 

So let's begin, please excuse my messy drawings 😀

If you want to familarise yourself with the wiring before-hand, two of the 3 connectors (Connector A and Conector B) that you are tapping in-to is under the window switch on the drivers door-card. You can simply pop-out the window switch panel and disconnect those two connectors and have a look at the wires in the first few steps below. This may help you understand better before you completely remove your door-card panel. The only connector that is only accessible after removing the door-card is the lock and unlock signal wires from the lock actuator connector.

  1. Firstly you will need to remove the drivers side door-card. This is because the drivers side door card has the master switch that operates the mirror. There are plenty of YouTube videos showing you how to remove the door-cards on the IS250.
  2. Once the driver's side door-card is removed, let's locate the 3 connectors that we need to tap in to. As I mentioned above, there are different variants of the connectors depending on region and variant of the car. The connectors we are going to be working with are as follows, I will refer to them in my illustration as connectors A, B and C:
    1. (A) The first connector that goes to the mirror switch panel
    2. (B) The second connector that goes to the same panel but controls power windows
    3. (C) The connector that connects to the door lock actuator. This connector is at the far end of the door and connected inside a round slot straight into the door frame itself. It looks something like the picture below:


  3. Now that we have located the 3 connectors that we are working with we are now going to need to connect all 9 wires from the mirror folding module system. Lets first have a look at the 9 wires and what they do in the diagram below. If you have a mirror module that doesn't match this setup, it should also have exactly similar function wires that you can match up.


  4. Now that you've had a chance to look at the 9 wires, we now need to make 6 of the connections out of the 9 wires to Connector A. Below is picture containing 3 illustrations to show which wires from the mirror fold system connect to which wires on Connector A. There are 3 different versions of Connector A and therefore in the illustration below I have drawn the wiring connections for all 3 different connectors. So please match the connector you have and follow the correct illustration. This is the only connector where you will cut two wires and create 4 open-ends to connect 4 wires from the mirror fold system.



  5. Now that the first connector is done. We only have 3 wires remaining to work with. Lets make the connection to Connector B. We are only connecting 1 cable to Connector B. There are also different versions of Connector B. And like the illustration in the previous step, please follow the conector that matches your car. From Connector B we are basically only interested in the always live +12v to keep the mirror module always powered.

  6. Finally, lets make the final two wire connections on Connector C. This is the lock and unlock signals. Please look at the illustration below to connect the correct wires to the lock actuator connector. If you want your mirrors to fold only when you double-lock (press lock button twice) then tap in to the thick white wire instead of thick purple as illustrated. 
  7. You should now have all 9 wires of the mirror fold system connected. 
  8. Test it by locking and unlocking the car. Please make sure the internal mirror folding switch is not pressed to the fold position as this will make the system ignore folding when locking. Once you are happy, tidy up the installation and secure everything and put things back in reverse order.
That's it. Enjoy your new convenient mod 😀