Now that the amplifier has been bypassed (see https://gransportmaserati.wordpress.com/2020/03/15/gransport-audio-upgrade-part-1/), we can proceed to installing the head unit.
The head unit comes with pretty standard stuff. The part we need right now is the wiring harness. This needs to be spliced into a generic ISO harness to plug into the cars factory harness. Although you can hack up the wiring in the car, I highly advise against this.
There are many different companies making the generic harnesses. Metra is probably one of the better known/quality ones. I went with a 70-9401 off Amazon (or any car stereo shop should have them too). You can find other ISO compatible harnesses, just make sure to follow the pinouts carefully as sometimes the colors/positions aren’t always identical.
The Metra harness matches up nicely with the Pioneer harness that came with the head unit. It’s simply a matter of matching colors from the Metra to the Pioneer and splicing them together.
Make sure to put quality joints here. I soldered each join, heat shrunk it, and then covered in electrical tape. Pay special attention to the wires with stripes/no stripes and ensure you’re matching these up properly.
At the end, you should end up with all the wires spliced except for the really long GREEN parking brake wire and the blue/white reverse wire. These aren’t need for the install, so I simply tucked them away.
Tidy up the bundle and secure all the wires with some more electrical tape and zip ties.
Next we need to remove the old Becker head unit from the car. Start by killing the main power shutoff in the trunk. While you’re there, try and find the removal keys. If you don’t have these, you’ll likely need to order some (they are dirt cheap from ebay/Amazon, or a stereo shop).
Insert the keys onto either side of the stock head unit in the small slots. Note that each key is embossed with the word TOP. Make sure this is facing upwards. Gently push and jiggle the keys until they go in all the way.
Once in, put your fingers through the two holes and pull gently. The head unit should just slide out.
As you’re pulling the head unit out, guide the cables coming into the back of it. Once it’s removed about an inch from the dash, you can start by removing the antenna connector (right) simply by pulling firmly. On the other side (left) are three wiring harnesses. They all have small catches on the right side that need to be pressed while gently pulling. The head unit should now be freed.
Another item you will need is a antenna adapter. This is Metra 40-VW12 which seemed to be the most compact solution. There’s other options as well (just make sure the male/female ends match this one).
The stock antenna cable simply clips onto the adpater.
Before going any further, I like to test the wiring first. Simply take the adpater harness that you created and connect it to the stock wiring. You will only use the large black and large white connector. The tri-color connector is for the CD changer input and we will no longer be using it. It can be carefully tucked back into the dash. Plug the other end into the headunit, and turn the vehicle power back on. I verified that the unit turned on, and that all speakers were working.
Turn the power back off, and remove the head unit again (leave the adapter harness connected to the vehicle harness). The next step is to install the mounting cage. This came wrapped on the head unit itself out of the box and so you need to start by removing this first. Use the keys included.
Slide the cage into the dash opening until it sits flush and wont go in anymore. You may need to jiggle and push it a bit as some of the rivets get in the way slightly. Then fish out the antenna and harness connectors and feed them through.
Using a small screwdriver press some of the retaining tabs around the perimeter of the cage to secure it into the dash. For this install we want to use the ones closest to the front. You don’t need them all, just enough to prevent things from wiggling.
Connect the harness and antenna back into the head unit. You need to take the excess wire and tuck it all UNDER the cage to leave clear space behind the opening to permit the head unit to be pushed in all the way. This took me a few tries to ensuring things were clear.
Push it in all the way until it clicks into place. It should be secure now at this point.
Install the trim ring next to finish it off. At this point we’re pretty much done. Setup the mobile app, and install your phone into the holder. I recommend you buy a short lighting cable as well (6″ or so) to plug into the USB port.
Looks good and not too intrusive in the interior.
Without the phone mounted, it doesn’t look to out of place/out of era from the factory head unit. The head unit can still be used for basic functions without the phone (radio, BT audio, etc).
Sound quality is good too. A big improvement over the stock system. The speakers are definitely on the list for the step in quality.