1995 456 GT. When I got the car a year ago it had a voltage leak at the + battery terminal (continuity between engine block and + termina)( I manged to isolate the leak to the "cigar lighter" fuse circuit. This had an overisze fuse in it (go figure) and when I pulled it out the battery leak went away with no other leaky fuse circuits. I've pulled the console apart to replace the shifter space so I figure now is a good time to find that leak. Test conditions:. Battery ground switch off (no ground), cigar circuit fuse pulled, ohmeter hooked to shifer box and electrcal connectors removed from: lighter lighter lamp ac controls hazard fog parking lights reverse light mirror adjust. Test results at disconnected connectors: All black wires complete circuit (as they should). red/black and green wires on revese gear always complete circuit. red/black wires on cigar lighter completes circuit when car doors opened, but not closed (coupling test). red/black wires on ac controls never complete circuit, but yellow/red and orange wires do complete circuit cigartte cover light completes circuit when cover is in open position (light on) green wire on mirror adjust always completes circuit. Couple of questions: Does red/black and green wires mean something in Ferrari wiring diagram? Like a switched 12v lead or somethng? Is green an alternate ground? Where to look next?
I am pretty good at electrical diagnosis and your testing leaves me totally confused. What is the symptom? What are you trying to fix?
Sorry I guess I was not clear. There is a parasitic drain on the battery. With ignition off and key out it drains the battery. I believe It is in the cigar lighter circuit. It goes away when I pull that fuse. The P.O. put an oversized fuse in that circuit which leads me to believe I have a short somewhere in that circuit.
Ken, this is the way I proceed when tracing a leaky circuit: 1. Leave the key switch off and the battery earth switch closed. 2. Pull fuses in the fusebox 3. Set your DVM to resistance; ground one lead of the ohmmeter and with the other lead, probe the circuits at the fusebox on the LOAD side of the fuses. When you find the circuit that shows a lower than "normal" resistance to earth, then start working your way further downstream, as you've done, by disconnecting electrical connectors, removing devices from the system, etc. until you find the circuit or end device that changes the resistance reading.
