Thread: Electrical woes

you really need to buy the wiring schematic for your year. 2.4 is different to 2.2 in respect of body harness coming from the ECU. you can find on the web the wiring schematics for both versions. be careful some are in a foreign language.

in the 2.4

speedo and fuel gauge - receive signals direct from source and not through ECU. As such gauge failure seems to be related to power or ground to the cluster
tacho is a canbus signal from ECU to instrument cluster. I doubt you are losing the canbus signal and my money it is common to the speedo/fuel gauge problem
engine losing power - there could be several sources for this. It's known problem in the puma instrument cluster if the immobiliser signal is interrupted (dry solder) the serial signal from the 10AS to ECU is interrupted and that could cause the ECU to think its being immobilised. ECU controls fuelling as part of the antitheft system. The other is a power or gnd fault to the ECU (including the ignition +ve signal to wake up the ECU. ignition also wakes up the cluster).

i would start on the power schematic upstream of the ECU and instrument cluster and see what circuits/relays are common to the ECU and cluster. Start from the battery and work your way to the end point (ECU and cluster). On the 2.4 the instrument cluster gets it's power from the fused junction box that also supplies the ECU but is not on the same power circuit as the ECU after the junction box. the cluster receives a constant +ve from a fused junction box and ignition switched. The ECU receives its power from the main relay, that is, ironically, controlled by the ECU. Don't dismiss a faulty ignition switch which controls the wake up signals to both. Your android installer may have tapped into the ignition power wire and disturbed the termination to the ignition switch.

i doubt turbo or fuel pump (2.2 only) as items are the problem of themselves, but more likey electrical that controls those items. lights, engine monitoring and air suspension is likely on a different circuit to the problematic circuit. lights will pass through light switch and has nothing to do with the ECU or that circuit. engine monitoring and air suspension if aftermarket will be on a different circuit independant of the engine and body harness. I run air suspension the main power is wired direct to battery and an ignition switched wire to wake up that ecu.