Technical code and injector fault light wiring

[Prawny12009]

Are the wires from the ecu and code box to the lights fed from the ecu/code box or earthed by them?

trying to figure out if i need to put a switched live to the other side or aftermarket idiot lights or earth them out before i start making my loom.

 

[lukew]

I want to say the lamps need a live feed but not 100% on that. I can check tomorrow while I'm fixing more wiring faults

 

[Prawny12009]

I was a bit too eager pulling the loom apart forgot to trace the dial side wires, I traced the ones from the code box and ecu and just cut the rest.

I've got main power/ thick white 20A switches to red on engine harness, switched power/ thick orange to 7.5A fuse changes to thinner red-black then back to orange/orange-white for ecu and code box but I wasn't sure about the dash warning lights, it's possible one of the other wires splices i cut from the switched live also went to dash lights.

I guess code and fault lights aren't vital to functionality anyway otherwise the car would die if a bulb blows right?

I did spot a little diode (1n4004) and pretty big 100 ohm resistor on the pcb in the clocks for the battery warning light though, A diode in series and a resistor in parallel.

I'm guessing that was how fiat stopped the battery light back feeding the ecu relay/ switched live circuit, a diode to prevent a back feed and a resistor in case the bulb ever blows so that the circuit doesn't fail preventing the alternator from working.

 

[Prawny12009]

you are right they are live from the car and earthed through the ecu and code box