Well I just checked and the wiring / colours on my 500X are not the same as on the Tipo. Why of why can't Fait come up with common colour and usage conventions.
Moving on.
On my 500X I have the same twin bulb that is modulated to give side lights at a lower voltage and brake lights at full voltage using the same pair of bulbs in each of the rear clusters.
I got fooled by Fiat as they had separate wires for the side lights and brake lights when in fact the system operates differently by using two voltages and having both bulbs and side lights and brake lights.
So I wired my PCT ZR2500 up with all wires connected an then found a wee little oddity.
When the sidelights are on the caravan sidelights and front top Red/White corner lights come on. With sidelights on and press the brake pedal the trailer/caravan brake lights come on. Brilliant.
Then I noticed with side lights off and pressing the brake pedal then the caravan side lights, top corner lights and brake light come on.
To get round this the ZR2500 can handle multiplexed (which Fiat fooled me to thinking I did not have). All you have to do is drop one wire off.
Having finished and put everything back I decided to leave as wired. Perfectly legal and actually now when I press the brake pedal I get on the caravan: High Level Red, Brake Red, Sidelight Red and top Corner Red marker lights. Blinking Christmas Tree
One day when I'm behind all the boot covers etc. I may snip the offending wire but to be honest I quite like the fact that I have so many rear brake lights
3 high level, 4 main.