strange wires

[ssc1]

i have an 86 350i ,that the alternator has just failed on but what i am asking is , there are four wires coming from the drivers side injectors three are blue and one is red and they are all joined up together and attached to the back of the alternator -side they look like some one has just added them on as there are no extra ones on the other four injectors apart from the usual wires that go to the ecu. now these extra wires look a bit gash and are not factory fitted so does some one know why they have been fitted and does anyone elses wedge 350i have these extra wires going from the injectors to the alternator.......ian

[wedg1e]

I'd be wanting to find out whether they have 12v on them. If they do, are the injectors the right ones for the car? Could be someone has bodged it... the standard injectors aren't fed with 12v, they get a reduced voltage from the resistor pack on the l/h wing.
Maybe someone has fitted the wrong injectors, they need 12v so they've taken the feeds from the back of the alternator.

Wild stab in the dark...

Ian

[GreenV8S]

Sounds like somebody may have earthed that bank of injectors to the alternator. Which makes sense if you're desperate to fix a problem or suspected problem with the injector wiring (assuming you have got the injector ballast resisters wired in correctly), but is really naff as a permanent fix.

[wedg1e]

Peter, the injectors have an ignition-switched positive feed via the resistors, and are earthed by the power transistors in the ECU switching.
Either way it sounds like a bodge...

Ian

[ssc1]

well the wires are aditional to the normal ones that go to the resistor pack but what i cant understand id why earth them through the alternator and only the left hand bank of injectors, the car runs great but it just looks a right bodge and if its to clear a fault then its four new injectors then,as i cant see anything else that would cause this job to be done, unless that resistor pack was buggered....where can i get a wiring diagram for the rover fuel injection system,,,and does thewedge book have it in (the steve heath one).....ian

[bluewedge350]

Obvious question but does it run any different if you disconnect them... J

[ssc1]

have not been able to run the car without these wires as the alternator was buggered, but now got a nice recon unit for £65 so i will try it tomorrow without these wires connected.....ian