How To: LED MOD 2005-2006 tc HVAC
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[edit] HOW TO: 2006-2006 Scion tC HVAC LED Mod
"Disclaimer: This is a write up on the process for changing the color of the HVAC lighting on the tC. I take no responsibility for what you do to your car and any mistakes that may occur. - Dave (aka engifineer)
This is the newest incarnation of the HVAC mod for running blue, green or white LEDs.. If you are running red LEDs or are only swapping the gauge LEDS, then you do not need to perform this mod. As always, I take no responsibility for anything you may do to damage the board. The mod itself works, but you always take a small risk of damaging something when you begin modding.
I have calculated the circuit components and obtained datasheets for the power supply IC, so I am confident it is all in spec and properly designed. As with all of these DIY posts, I take no responsibility for anything (broken LCD, wife leaving you, meteor falling on your house, etc tongue.gif ) But I am a trainied electronics engineer and have taken the circuit effects into consideration
Before beginning, it is a good idea to determine if this is a job you want to tackle if you do not have a lot of experience with this. Below is a list of what is involved:
1. De-soldering the LCD for the clock. This is probably one of the more tedious pieces. This takes some patience to do right and can result in a broken LCD, which is replaceable only through purchasing an entire HVAC module. So be careful on this step!
2. De-soldering all LEDs and some surface mount resistors. These parts are very small, so be ready to work with tweezers. 3. Soldering the new parts back in and soldering in the LCD
Tools you will need for this:
1. Soldering iron: 25-30W is plenty. Work quickly if you use a 30W iron. A temperature controlled iron is recommended, but I realize many may not want to spend $150 or so for one of these. You will need a small pointed tip for this (if using Cooper/Weller irons, I recommend an ETO or ETA tip).
2. Solder sucker: You can purchase a cheap one that is heated from Radio Shack or a similar store for around $10. Solder wick works great as well, but if you are not experience using it, the sucker may be a better option
3. Solder: You will need a small gauge solder for this.
4. Tweezers
5. Needle nose pliers: to remove the temp knob lock nut
Parts needed for the 2007 HVAC board
16 - PLCC-2 LEDS (18 if you want to do the gradient effect on the temp knob)
3 – 1206 package 43 Ohm SMT resistors
1 – 1206 package 130 Ohm SMT resistor
1 – 1206 package 420 Ohm SMT resistor
1 – 1206 package 680 Ohm SMT resistor
1 – 1206 package 560 Ohm SMT resistor
1 – SP-3SU package +10V regulator 1.2A rating
Ok, let's get started.
I don't recommend this if you are not familiar with or comfortable with soldering and wiring. I won't go through soldering techniques or disassembling the console, as this has already been covered in these other posts.
http://www.scionlife.com/forums/viewtopic....t=37747&start=0 http://www.yoursciontc.com/forums/index.php?showtopic=16155
I will focus on the circuit design. I will note one thing though. Be VERY patient with the LCD. Use solder wick and/or a desoldering iron, and move from one end to the other so you are not focusing heat on one area too long. It will seem they will never come loose, but there is solder all the way through, so it takes a while to get it all out. Don't try removing it until you can see all pins on the bottom move when you wiggle the display.
1. On the front of the board, de-solder the following parts:
a. R304 – Top left side of board, marked in red in Figure 1 below
b. R307 – Left of clock LCD. Marked in red in Figure 2 below
c. R312 – upper left of TEMP knob LEDs. Marked in red in Fig 3
d. R310 – Upper Right. Marked in Red if Figure 4 below
e. All LEDs you will be swapping
2. On the back of the board, de-solder the following:
a. R306 – Marked in red in figure 5 below. Middle – Right side
b. R314 – Behind the temp knob, marked in red in Figure 6
c. R316 – Behind the temp knob, marked in red in Figure 6
d. IC300 – Middle Right. Marked in Green in Figure 5
3. Replace the removed components with the new values listed below:
a. All LEDS removed previously
b. R304: 1206 package 43 Ohm SMT resistor
c. R310: 1206 package 43 Ohm SMT resistor
d. R306: 1206 package 43 Ohm SMT resistor
e. R307: 1206 package 130 Ohm SMT resistor
f. R312: 1206 package 420 Ohm SMT resistor
g. R314: 1206 package 560 Ohm SMT resistor
h. R316: 1206 package 680 Ohm SMT resistor
i. IC300: SP-3SU package +10V regulator 1.2A rating
4. This is a good time to plug the unit back in and test. Make sure to push all of the buttons and test all functions now so you don’t end up taking it back apart later.
5. Solder the LCD back into place. Be careful to move end to end while soldering so as not to overheat one area.
6. Clean all connections with rubbing alcohol and dry thoroughly
7. Plug in to test once again
8. Re-assemble HVAC module, install and enjoy!
Figure 1 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_Left.jpg
Figure 2 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_clock.jpg
Figure 3 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_Temp.jpg
Figure 4 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_Right.jpg
Figure 5 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_rear_PS.jpg
Figure 6 http://i4.photobucket.com/albums/y111/engifineer/2005_HVAC3_temprear.jpg
