Well we finally got it sorted out.
DISCLAIMER: This mod is quite nerve wrecking as you have to pull the head unit apart. There is a chance things can go wrong and damage can be done. Do this at your own risk, this guide is for your information only! There are also many different ways to install this configuration, below is the way we pioneered it which ‘works’. Where things can be done better with further time/money/parts I’ve indicated this. Feel free to make any suggestions/comments necessary but keep in mind we are not an autotainment spe******t, just a bloke with an SSV and a desire for a decent touch screen GPS!
So you’ll need the following:
• Garmin GVN 53 installed and functioning with the RX and TX wires connected to the Garmin wiring loom ready for connection to the TSC-205IM.
• 12 VDC supply ready for connection to the touch screen controller (from the same place you sourced the supply to the Garmin will be fine).
• TSC-205IM Garmin touch screen controller – I bought mine from HVI Electronics, firstname.lastname@example.org http://www.hvi.od.ua/
• A 6.5” four wire resistive touch screen overlay. Measurements indicated nothing bigger than 155mm x 89mm (this is important, we broke the first one – it was never going to fit as it was a few mm too long and we cracked it trying to push it into place). You can get these off eBay for around ~$40. We also went for one with the ribbon sticking out the bottom in the center as we found we could get it out and wired back to the TSC unit (see below for photos).
• A thin plastic sheet to cut out a frame to place over the touch screen overlay (explained below)
• The Garmin GVN 53 v2.50 downgrade kit (explained and linked below).
• A login to myGarmin/webupdater (https://my.garmin.com/mygarmin/login...RegDetails.htm) with the ability to link your Garmin GVN 53 to the internet/computer/laptop via the USB cable in order to download the latest Text to Speech (TTS) and software upgrades.
• General electrical tools and knowhow.
• A small (~30cm) strip of ribbon wire (4 cores) to extend the connection between the resistive overlay and the controller (as it’s too big to fit in the headunit).
• The willingness to remove your headunit knowing you may damage it! Removing the thing for the first time was absolutely terrifying and it felt like we were going to break it into many pieces, so be careful and if you don’t think you’re up to it – I suggest Turbocortys all in one solution (it has many benefits such as better Bluetooth and touchscreen climate control, I would have purchased one if I didn’t already fork out many dollars setting up my Garmin)!
• Luck and patience.
The touch screen overlay should look something like this:
This was our first attempt (which we broke) as it was too large and afterwards we realised the ribbon was in the wrong place anyway. Our preference for the ribbon is the bottom middle section of the screen. If you look on eBay there are a few.
Firstly we need to remove the front part of the headunit. The easiest way to do this is:
1. Disconnect the power supply/battery. I found if the power supply is left connected with the front panel removed error codes appear and the CD stacker doesn’t appreciate it.
2. Make sure the handbrake is on, put the car in drive (or change gears to make sure the gearstick isn’t in the way).
3. Place your hand under the screen, you can feel behind the panel, it’s about 1 inch thick, take hold firmly and pull it towards you. It has clips on it that will release (You should not break it, we tried many times).
With any luck you’ll have a disconnected panel you can begin work.
From this point onward – KEEP THE PANEL WITH THE SCREEN FACING DOWNWARDS AT ALL TIMES. If you turn it over, the plastic buttons and other gadgets will fall out with the metal cover plate removed.
Take your time and remove the screws, try and remember what one fit where. Remove the metal panel.
Now remove the screws holding the PCB in place. Be careful not to damage the connecting cable to the hazard light toggle switch (red box). It’s not necessary to remove the switch, but if you do be delicate with it, it’s a pain to put back in as from memory it’s spring loaded. The large metal section up the top right is part of the casing for the LCD screen, which is what we want to remove in order to place the touch screen overlay in.
Disconnect the ribbon in the blue box and also the larger ribbon above. Be gentle, with a small screwdriver or your finger nails you should be able to manipulate the plastic clamp which frees the ribbon. Now remove the PCB to get at the screen. Two people to do this helps.
The LCD screen can now be removed and the touch screen overlay you purchased can be placed in front of the screen (now is probably a good time to give both the overlay and the screen a bit of Windex). Before you insert the touch screen you need to cut out a rectangular frame from thin plastic that will provide a space between the touch screen and the front plastic bezel. This ensures that the touch screen does not have any pressure on it when installed in its final place. The frame only sits on the outside extremities of the touch screen (i.e. on the outside of the copper strip). Only one side of the screen should respond to touch, so you may want to connect the screen up to the Garmin or a computer via a USB controller to figure this out. Personally before we started any work we plugged it into the TSC unit and hooked it up to the Garmin to see if it responded.
Given our time again we would have done things differently here. On the TSC unit (below) you will need to connect the touch screen overlay into the small PCB shown on the right. We believe a better way to install the unit would be to purchase the connector on that PCB and wire from that to the main TSC unit. This won’t require you to locate the whole section of PCB plus both connectors in the head unit (real estate is scarce).
Not having the patience for this we found a place to fit the PCB. On the photo shown below we located a gap in the plastic cover to the panel where the PCB fits in nice and snug. We were mindful to make sure the metal prongs extruding (we assume this is a ground/earth) was still able to connect to the frame of the LCD. We also removed and replaced the wiring between the units with some ribbon strip we had in order to run this out to the main unit located external to the panel.
We found the best place to run this was out the top right hand side (or left depending on which way you look at it), as there is a pre existing space for the cable to fit through. It is a very tight fit. There’s probably many different better ways to do this but we found this way didn’t require a lot of filing to make a slot in the panel.
Now proceed to screw everything back into place, make sure the buttons still work and everything is OK. We did a sanity check on the cable length once I figured out where I would locate everything and then cut/soldered and heat shrinked everything to finish the connection to the TSC unit. Now the panel is ready to be reconnected and battery connection restored.
Depending on where you installed your Garmin will depend on where you want to locate your TSC unit. We made up a bracket from the cheap metal out of one of the DIY solenoid keyless entry kits from Supercheap auto (used back in the days when we had a Holden VK, but that’s another story) and mounted the Garmin on the left hand side of the head unit.
You’ll need to calibrate the screen first, but we found that when the front panel was removed there is a gap either side between the plastic frame holding the head unit in place and the panel. After taping the unit up we slipped it in the new found space and it’s been working well ever since (sorry I didn’t take a photo of this). We didn’t notice any ventilation requirements or excessive heat so we believe it should be OK. You won’t be able to get to it to maintain it but we're hoping we never have to. The issue with relocating it further away is the longer the cable length is between the touch screen and the unit the higher the chance the screen will be unresponsive. Remember it is a resistive touch screen and adding cable length to the touch screen circuit adds resistance which may confuse the controller!
The unit will have a TX, RX and Power (+ and -). Wire up 12 VDC to the + and – connections, then connect the Garmin Purple wire to the TX and the Grey wire to the RX. If you’re using the RGB activation module with head unit controls you’ll need to disconnect the RX link in order to allow the touch screen to work.
To calibrate the unit you need to first configure the TSC unit, then the Garmin. To configure the TSC unit follow the video Vitaliy created here:
tsc-205im connect to gvn53 _ 2.AVI - YouTube
So with the unit connected and powered on, one green LED (Power LED) should light up, indicating that it has detected the touch screen and the Garmin, if this doesn’t occur, something isn’t connected correctly or the unit is faulty. Short the two metal contacts on the TSC unit together (1:34). Once this is done, the second LED (Configuration LED) should start to blink at a set time interval. Now the TSC unit is in configuration mode.
As the touch screen can be installed at any angle you need to tell it which corner is which. To do this, touch the Top Left, Top Right, Bottom Right, Bottom Left and Centre regions as shown in the video (order is important). The power LED will blink rapidly to indicate that a touch event has occurred. The configuration LED will continue to blink at set intervals, but will change the number of blinks between intervals depending on which stage of configuration you are at. For example, once entered into configuration mode, it will blink once, indicating it is ready for input one (Top Left). Once you have touched the top left portion it will now start to blink twice, indicating it is ready for the second input (Top Right) and so on until it has accepted five inputs. Check this indication to make sure it has detected each touch input and in the correct order. We believe you need to then short the contacts again and repeat the process to confirm as shown then the touch screen should be configured and ready for use.
If the touch screen does not respond as shown at 3:19 but the TSC unit indicates a touch input the TSC controller is set to output touch commands to the wrong unit. The TSC unit is designed to control multiple devices, for example you may have a Car PC and a Garmin, with one touch screen and you cycle between the inputs. To change inputs touch the top right hand section of the screen for more than 3 seconds and repeat the process until you are able to control the Garmin unit. We found the unit then stays on that ‘input’ and I haven’t accidently swapped it as most touch events don’t last more than ~0.5 seconds.
The next bit of the video (3:50 onwards) shows how to calibrate the touch screen with the Garmin unit. This stumped us as our unit did not have a “Calibrate Touch Screen” button! For some reason, v2.50 of the Garmin GVN 53 software doesn’t have the calibrate function, so you’ll have to downgrade to v2.30, calibrate as shown in the video at 4:00, then update back to v2.5 again.
To downgrade the device, download this – http://www.filefactory.com/file/ce66...downgrader.rar then follow the instructions as shown here ver2.3 to ver 2.1.AVI - YouTube. We found our touch screen was so off we could not select anything after the upgrade, so make sure you have the Garmin remote handy. We also found we had to re-pair the remote with the unit after upgrading by holding down the thumbstick and 0 for 10 seconds, then entering the code that appeared. Once you’re up and running again run the configuration, make sure you’re satisfied with your selection then use the myGarmin webupdater to revert back to v2.50 (We believe this is a significant advantage upgrading as the TTS improves dramatically).
Finally tidy up any cabling, replace panels/covers and restore your car to a workable state.
All done!! The finished product should look something like - Garmin GVN 53 Touch Screen Modification - YouTube
Something else to note: I’ve found the touch screen to be an essential part of the Garmin unit and typing in long street names is now an easier task. Resistive touch screens are old technology, not on par with capacitive screens used in devices such as Android and iPhone smart phones. There is also a small delay with the unit when selecting items. In order to get the most out of our touch screen we’ve found the best way to use it is to place your finger on what you’re after, then wait until it has been selected before removing the touch input. Spending the extra milliseconds on each input makes the whole process go a lot smoother.
Oh and as a teaser to the autoswitch module/reversing camera – see if you can spot where I installed the reversing camera!