I'm in the process of installing a system in my truck using the following wiring harnesses, tapped into a MTX re-Q.

http://www.sonicelectronix.com/item_...a+70-5520.html

http://www.sonicelectronix.com/item_...71-5520-1.html

I got everything connected up, the radio and the LOC turn on, but I have no steering wheel controls. So far with the 5520-1 harness, I'm only using the 24 pin connector. Here are the wires I have not connected to anything:

71-5520-1 (24 pin) male
orange/white illum +
orange/black illum -
blue/red PAEN (US), AUD. SYSON (Mazda)
black/green GROUND (MAURADER), CLOCK (OTHERS)
black/yellow PTA (EXPEDITION)
grey/red VSS (+)
red/white 12V. IN START
yellow/orange NO FUNCTION
yellow/blue NO FUNCTION
green/red STEERING WHEEL CONTROL +
grren/white STEERING WHEEL CONTROL - (EXPEDITION)


71-5520 female
blue power antenna
blue/white amp turn on
orange/white dimmer

I know I need the steering wheel control wires hooked up...but where? Here is the manual for the 5520-1 harness, showing what's on the other plugs.
http://metradealer.com/files/products/INST71-5520-1.pdf Thanks for any help. I appreciate it. -Mac

 

I am in the process of doing the exact same thing. The 70-5520 which is a female end needs to have some wires changed to make the steering wheel controls work. It didn't have them in there. So what I did, is pulled 3 wires that I didn't need in this application and put them in the correct position. You have to pull the red cap out of the plug to gain access to the wires. It is hard to explain, but I switched the wires to were the factory wiring harness had the wires and it worked. I will try and take some pics of it, as my dash and radio are torn all apart at the moment.

What I can't find is a remote on lead to turn on my amp. On the 72-5520, there is a red and white wire that says 12V start. I thought for sure that would do it, but it didn't. So now I have to find a key on wire somewhere to fire up the amp.