2006 G35 Coupe Navigation system replacement.

First off thanks to Wrathernaut for his excellent article on how to remove and dissemble the G35 Nav unit. It’s what got me motivated to try this upgrade.

I am sorry that I did not document the steps of the project with pictures, but I will try to explain the basics of what I did.

After a lot of research I chose the Garmin SmartDRive 65 as the replacement unit for several reasons:

I like Garmin and have owned several units in the past. The 7 inch SmartDrive unit was an almost exact fit for the existing G35 elevator unit. The Garmin is a completely self contained unit, no external GPS antenna or speakers. I thought that might make the conversion easier.

Projects like this often require some experimenting and tinkering to take care of all the things you didn’t know about at the outset of the project. With this is mind I purchased a used elevator unit from Ebay for about $50.00. My strategy was to do all my experimenting and tinkering on this unit and avoid a long down time on my G35. Hopefully I would end with a fully functional unit that I could then simply swap out with the original factory unit in just a couple of hours of down time.

I was able to get the donor unit operational on the bench fairly quickly, just a few simple power and ground connections. I dissembled the unit following Wrathernaut instructions. I removed the old display and related electronics. I did some careful measurements of the elevator box and did some eyeballing of the unit in operation trying to foresee any problems that might hinder the conversion.

I had held off on actually purchasing the Garmin unit until I could get a chance to see the elevator unit in the flesh. At this point I was confident the conversion would indeed work, so I committed and ordered the Garmin.

While waiting for the Garmin to arrive I cut the back and top out of the metal elevator box. This was (per Wrathernaut suggestion in his article) in order to allow for GPS reception since the Garmin’s GPS antenna is self contained.

The Garmin unit arrived and a quick test fit confirmed that indeed everything was going to fit perfectly.

The Garmin’s horizontal size was a perfect fit for the box. The vertical size was a little smaller and the depth of the unit was significantly smaller. The display screen size was a perfect fit for the existing G35 factory frame, so no modifications were going to be needed there.

I decided on fabricating a wooden cradle that would hold the Garmin securely in place in the elevator box. I chose wood because it is easy to work with, would not block the GPS signal and would not scratch the plastic Garmin case.

With the Garmin successfully physically mounted, it was time to turn my attention to the electrical connections. The Garmin has several options for power. The unit internally runs on a 3.7 volt Lithium rechargeable battery. The unit can be recharged or powered by a USB cable or a 12V cigarette lighter factory cable. I wanted a solution without dangling cables or extra switches to mess with. I wanted the Garmin to power up and down in concert with the elevator just as the original factory unit.

12 volt power was available via the factory connector to the elevator unit and properly controlled by the ignition switch. I decided the easiest and safest way to power the Garmin was to use the supplied 12V cigarette cable. I cut open the cable housing and removed the electronics. The electronics from the cable could easily be mounted in the space previously occupied by the elevator electronics. A little wiring and soldering and all was complete.

Now the problem was how to get the Garmin to power on/off in concert with the elevator. It turns out there is a connection in the factory cable that signals when the elevator is up/open. It is controlled by a limit switch located on the elevator unit. The signal is +5 volts when the unit is open. Without knowing what the internal circuits of the elevator unit were I did not want to try and power the Garmin directly from this signal wire. I also discovered that you can’t simple hijack the limit switch because it’s required by the elevator circuitry to stop the downward movement at the proper time.

My final solution was to use a small low power reply between the limit switch and the Garmin’ power electronics. This seemed to make the elevator circuit happy also.

I could have wired the Garmin’s audio output into the G35’s audio system but it seemed unnecessary. The Garmin has a small built in speaker and it seems very sufficient in volume and clarity for use inside the G35. The factory Nav installation includes a “ducking” circuit. It reduces the volume of the normal audio stream when the Nav unit is speaking so that the Nav unit is sure to be heard. That’s was something I didn’t want to get into providing right now, maybe later.

A few other little odds and ends had to be taken care of. I drilled a small hold in the top of the elevator unit so the Garmin’s microphone could hear into the G35 cabin. I also drilled a hole at the rear of the elevator unit for the Garmin’s speaker .

A final bench test and I was ready for a swap into the G35 which did go smoothly. You do have to remove a portion of the console to get to the unit. You can find several videos online that show how to do this. A couple of hours and I had the new Garmin elevator unit installed and working.



The Garmin is very happy in its new location. The voice controls work well and the Garmin audio can be heard easily inside the cabin. GPS signals are strong. What I like best is that it looks just like a factory installation. Once again, many thanks to Wrathernaut for his excellent dissemble video.

 

Thanks for the write-up, always good to see people still experimenting on these cars. If I get really bored, I might look to relocating the touchscreen of an aftermarket radio to sit in my elevator, as mine has been reduced to housing a magnetic mount for my phone - Galaxy Note 10 - that's too large to fit in the opening. Ideally I want to get a headunit that will simply mirror the android screen, and have radio functions as well.

How's the microphone reception doing up there?

If the case of the garmin is fairly easily disassembled, I think doing that and relocating the mic and speaker to face front would be better for clarity when the car is in motion.

 

I'm glad that you found out a way of utilizing that spot as its pretty cool that its concealed and moves up and down making it an ideal location for some type of modern tablet instead of the factory old school unit it comes with. The only issue that I see here is that it is way too much work and money to install a Garmin GPS system this day in age. Just due to the fact that Google Maps is so much better than Garmin and with a tablet you have other options like being able to watch videos, listen to music, use more modern GPS systems, make calls, etc....... Do you know if there is any other type of tablet that might fit in that area?

 

To completely fit in there, you're looking for a 6" or less tablet. So long as you can script the screen timeout and such so that it go from "sleep" mode to always-on quickly, and tether to a phone (or have its own data connection) it's only a matter of cutting out some black plastic and/or foam to mount it with proper power. Depending on the unit, heat may also be an issue.