| Author | Message | ||
     Bob Reynolds New User Username: bobreynolds Post Number: 5 Registered: 8-2012 |
I have a 1975 Shadow with electrical problems. It seems that half the electrical equipment on the car doesn't work! The right-hand cluster of warning lights on the dashboard has a green wire going to it, which delivers 12v from the ignition switch (fuse 11). The left-hand cluster also has a green wire, but no 12v. The circuit board behind the dashboard also has the green wire going to it, but no 12v. Now, these 3 wires disappear into the loom at roughly the same point, so I can't understand where the disconnection can be. The loom is not damaged in any way. It may be that this green wire goes from the right-hand cluster, all the way round the car and then comes back to the left-hand cluster, but that's not very likely (but possible I suppose). How is it possible to tell the routing of a particular wire from the wiring diagrams? I can understand the Theoretical diagrams perfectly well, but the Wiring diagrams leave me totally confused. Is it possible to trace a wire from one point to the next, using the Wiring diagrams? | ||
| Jeffrey McCarthy Grand Master Username: jefmac2003 Post Number: 329 Registered: 5-2007 |
Bob, the practical wiring diagrams can sometimes help but I find them best for locating and identifying connector blocks by wire colour. Eventually though the theoretical diagrams come in very helpful; it is thoroughly worthwhile learning to follow them and is not as hard as it looks. I had mine blown up to about 3 metres by 1 1/2 metres and laminated :the shop joined the pages using Adobe first. It cost about AU$80 though. This particular green wire circuit has had me stuped for a while as well. A small continuity tester at least helps figuring out what's connected to what - I suspect your non 12v green wire only becomes active when something else down the line happens. Which particular non-working electrical thing are you trying to fix at the moment? | ||
| Bob Reynolds New User Username: bobreynolds Post Number: 7 Registered: 8-2012 |
The right-hand warning light cluster works, but none of the left-hand ones work. There is no 12v on the green wire on the left-hand cluster, so none of the bulbs work. The continuity is broken somewhere between the left-hand and the right-hand light clusters. I have made a list of all the green wire connections that have 12v on them (fuel gauge, oil pressure lamp, etc) and those that don't. But this doesn't help me unless I know the physical route that the green wire takes. The break could still be anywhere. I know I can simply connect a wire between the non-working connections and the working ones, but this would bypass the fault without finding the actual fault. If all else fails, this is what I will do. | ||
| Jeffrey McCarthy Grand Master Username: jefmac2003 Post Number: 331 Registered: 5-2007 |
Is it the green plastic wire that goes from the Low Brake Pressure Warning light to the High Metal Temp Buzzer? You'll need one of those cheap $10 continuity testers that Dick smith or Jaycar sell if you don't have one already. The Buzzer in question is behind and underneath about where the ignition barrel is - easiest got to by removing the trim around the handbrake (three screws) - it also has a Green/Purple Cotton [GP-C] wire on it. This wire shouldn't normally be live ... I think. My buzzer isn't working and as I said this circuit still stumps me. | ||
| Bob Reynolds New User Username: bobreynolds Post Number: 8 Registered: 8-2012 |
Yes it is that green plastic wire. Yes, the buzzer works, so the 12v is getting that far. Took me ages to locate the buzzer, even with it working! The GPC wire should not be live. It is earthed by the temperature sensor on the engine. or by the Test Switch. Either of these will sound the buzzer. |
