Hi all, I've just completed installing my new touch screen radio head unit, complete with installing the steering wheel control module.
After a bit of researching and inquiring around, I ended up installing the whole lot myself.
My Patrol is a 2002 4.8lt. petrol ST wagon, a bit of an old girl now, but still with plenty of life left in her, with nearly 300k on the clock. My wagon already has a cruise control module on the right of the steering wheel, but has no audio control on the left side, just a blank patch, ready for one to be installed.
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The head unit I choose is a Pioneer AVH-Z5250BT mainly because it can play DVD's as well as all the other functions. the manual control buttons on the side are a bit small, which I wanted to install a steering wheel control, so as you don't have to take your hand off the wheel while driving.
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Installing the head unit was quite easy. I used Aerpro patch leads to plug and play.
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Remove the dash pod from the bottom, and ease off the cover
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On the work bench is easy to install the new patch lead
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Make sure you connect the hand brake wire to the hand brake switch, this will be needed later to operate the steering wheel module.
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The above is the head unit wiring loom, with a handbrake wire also. I didn't need this loom, (as I used an after market one as above)
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Once all plugged in, the radio works. Just remember the head unit needs to be screwed back to the dash to earth the unit.
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These after market head units use your phone to access your maps for navigation. My phone is an android Samsung S10 and uses the Android Auto app to connect to the head unit.
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I've run the usb cable from my phone to the head unit, via through the dash from the windscreen pillar, to the head unit cable. I positioned the microphone close by there also (works well for the front seat passenger to use their phone calls too)
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I had a time connecting Android Auto to the head unit, until I worked out I needed to turn off "Remove permissions if app is unused" on the phone Android Auto app!
I didn't bother connecting a reverse camera to the head unit, as I already had one.
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So that's the easy part installed. Installing the steering wheel control module was a bit trickier.
I bought this secondhand switch unit from Nissan 4x4 auto spares in Victoria for a rip off price of $200
I think it is off a Nissan Maxima, from what I've learned.
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A bit grubby and sick colour, but I painted it a closer match to my wagons colour scheme!
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At first I thought the job of installing the switch unit would be a bit beyond me, so I contacted some professionals, but they all were no help, only good for installing new radios and spotlights!
So after some research, and checking this Forum, particularly, "Cremulator" (thanks mate) I didn't have much choice, but to do the job myself.
The main thing is getting the switch signals through the "clock spring" (the coiled wiring passing through the turning steering wheel)
Luckily, there is 2 spare terminals in the clock spring to use.
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There are 2 plugs that go through the clock spring, one for the air bag, and the other for the horn and cruise control. We leave the air bag one alone, and use the other one.
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Then make up a new wiring loom to join the audio switch and cruise control switch, to then insert into the clock spring plug, on the steering wheel side of the clock spring.
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On the other side of the clock spring (on top of the steering Colum) I connected another new wiring loom, to run to the head unit. I couldn't open the plug there, but I was able to insert the terminal pins into the plug contacts.
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To get to the head unit, we need to make up another wiring loom from the clock spring to the head unit. The Pioneer didn't come with the 3.5mm jack plug needed to plug into the head unit, so a $2.15 plug from Jaycar doses the job.
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It is a 3 wire plug, 2 active and an earth.
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The earth tag, I connected to the head unit mount.
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So with the wiring pacifies, this is how it works:
The audio switch module came with 4 wires, and a horn wire. The extra red wire on it was not needed, and also the extra horn wire.
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The control system works on the amount of resistance in the button selection, and what wire it travels through. This can be checked with a multi meter.
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Some have different readings, but some are the same, but they use the other of the 2 wires. Quite clever. So this is the way we can operate the 6 button commands, through 2 wires!
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The yellow wire on the switch is the earth wire, so we connect that to the green wire on the cruise control, earth wire.
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The above photo shows where I mistakenly connected the switch yellow earth wire, to the cruise control yellow wire. where the button commands didn't work too well.
So the earlier photo of the made up wiring is correct.
I heard it is best to soldier the joints where possible to help keep the resistant levels in place.
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Shrink wrap is ideal over the joints, and a hair dryer will do the job, if a gas torch is not available.
For the extra terminal pins needed, to install in the clock spring plugs, Jaycar comes to the party for a set of 4 terminals for a couple of dollars.
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They are not quite the same, but do the job.
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So once all is connected, it's time to tune in the audio switch to the head unit
On my head unit, to set the commands, turn on the radio, power off the unit with on/off button on the radio, turn on again, go to AV source settings and turn off any AV apps there, like blue tooth and spotify
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Then go to Steering wheel control, and follow the prompts
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Some head units require an interface module, to allow the steering wheel switch to work. This one has an inbuilt unit, so we choose W/o adapter on the screen.
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These are the choices I made for the 6 buttons. You can choose what command you like, of the presented choices.
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I painted the desired choice on the buttons, until I can find some stickers to Suit!
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So, in summing up, it was relatively easy to install the whole system, once I learned what to do. Just need a few basic tools and are ok with working with your hands.
Now I can drive and operate the head unit and phone hands free!
Feel free to ask any questions, Cheers.