| Author | Message | ||
     Daniel Diewerge Experienced User Username: didi13109 Post Number: 19 Registered: 11-2009 |
On my Bentley 8, X13109, I probably have a bad connection from the alternator to the interior or fuse box. The voltmeter reads around 12,5 Volts with the headlights on and the engine running of course, it never goes any higher than 13,3 Volts at minimum load. This of course has negative effects on all electrical devices. I had the Motorola alternator prophylacticaly rebuild and the output is at a very stable 14,03 Volts at the alternator as well as on the battery pole, no matter how much load I put on the electrical system. Since I get this low reading on every connection I measure under the dashboard, I assume that the fuse box itself does not receive the full current. Lying headfirst on the floor to eyeball the fuse box, I could not find the connection, neither could I trace it in the engine compartment or find something in the technical library. Could someone on this forum please steer me in the right direction? Thank you! | ||
| Jan Forrest Prolific User Username: got_one Post Number: 246 Registered: 1-2008 |
I'd be more inclined to suspect the 'common' connection points along the electrical pathway: Battery terminals Earthing points The output lead/connections on the alternator The main positive cable from the battery. Any excessive resistance in even one of these will result in lower voltages appearing in the sub-systems such as the fuse box which will worsen as the load is increased. | ||
| Daniel Diewerge Experienced User Username: didi13109 Post Number: 20 Registered: 11-2009 |
Thanks Jan, that is what I supposed first. But I have strong and stable voltage at the alternator output and the battery terminal. Cranking power is phantastic so the problem must be somewhere between the main battery/ alternator cable and the fusebox. Is there something as a main plug where the loom goes into the car. The plugs on thhe right and left side firewall seem to not contain the main power cable with should be of a thicker gauge than the other wires. Thanks! (Message edited by didi13109 on 23 September 2011) | ||
| Jan Forrest Prolific User Username: got_one Post Number: 247 Registered: 1-2008 |
I'm not fully au fait with these later models of Rolls', but as they're often classed as Series 3 Shadows many of the electrics will be much the same. The next port of call should be the workshop manuals for the Shadows and then the Spirit etc taking into acount the many minor differences. With these cars being far from the first flush of youth it's not unusual to find minor damage and/or corrosion to the various loom connectors which can be cleaned off with 'switch cleaner' or even a thorough dunking in a medium strong solution of hot citric or acetic acid. If using the acids the connectors will need a while to dry out afterwards. Either way filling both sides (when dry) with petroleum jelly should keep the tin eating monsters away for several years! The only problem I have with car electrical circuit diagrams is that they bear little relationship to, or indication of, the actual physical locations of the items they describe. | ||
| Daniel Diewerge Experienced User Username: didi13109 Post Number: 21 Registered: 11-2009 |
Hi Jan, that is excactly my point. In the workshop manuals I cannot find the exact location of the main power wire to the fuse box. If I would know where to look, I would check/ clean and greae the plugs/ contacts. When I follow the thick gauge wire from the alternator, it ends up in some loom that I don't want to cut up. Thanks | ||
| Jan Forrest Prolific User Username: got_one Post Number: 248 Registered: 1-2008 |
Have you tried looking for another circuit that is also run through the same connector? Preferably something inside the car so you can trace the wiring back to that connector. |
