| Author | Message | ||
     KC Saayman Frequent User Username: kc_saayman Post Number: 44 Registered: 10-2004 |
The instrument lights on my ’74 Shadow stopped working. I have checked the fuse, and that seems to be fine (visual inspection only) Is there a relay on this circuit? If so, where do I find it? Is there anything else I should check? Incidentally, I did a search of the archives, but found nothing. Perhaps I am using the wrong key words. Hope someone can help. Regards KC South Africa 1974 Shadow | ||
| bob uk Unregistered guest Posted From: brig-cache-4.server.ntli.net |
I would check out the switch that works the brightness of the lights and the resistor that controls this. Check out the workshop manuals in the technical liberay. Also check the fuse properly first before you spend lots of time. The colour code for the instrument wiring is red for live and black for the earths. It is bound to be something simple assuming of course that the side and rear lights still work. Which reminds me check the parking light rotary switch under the dash board because this separates the left and right hand side lights and turns off the instrument lights. Some cars have a separate switch that completely turns off the instrument lights - I had an Austin 1100 so fitted and nearly took the dashboard out, I discovered that a small passenger had been playing with a switch that I did not know was there. (Message approved by david_gore) | ||
| KC Saayman Frequent User Username: kc_saayman Post Number: 45 Registered: 10-2004 |
Thanks Bob, I will perform all the checks you mention. I have since done a proper check on the fuse, and can now confirm that it is OK. I have also now noticed that the wipers do not work. Is there any possible connection between that and the instrument lights? To check the switch that controls the brightness of the instrument lights, I assume I must remove it. Is the resistor part of the switch, or is it found elsewhere. How do I test the resistor? The side and rear lights do still work, as you suggest. I do have the workshop manual, but it seems to lack this depth of detail (or I am just not finding it) Thank you very much for the help so far. I consider auto electrics to be a dark art, so I really appreciate all the assistance I can get. Kind regards KC | ||
| bob uk Unregistered guest Posted From: brig-cache-4.server.ntli.net |
Electricity follows logical rules and mathmatical formulii. To read circuit diagrams you need to logically study the wiring diagram. The instrument lights will have a supply and earth(s). The supply will come from one side of the side lights. For a light bulb to work it needs a supply and an earth ( postive and negative ). Turn the side lights on and check that the instrument fuse is live (12 volts ) at both ends. If it is not then the fault is before the fuse. Also turn instrument light switch on and off fast just in case the switch is sticky. (Message approved by david_gore) | ||
| KC Saayman Frequent User Username: kc_saayman Post Number: 46 Registered: 10-2004 |
This problem eventually got the better of me, so I dropped the car off with our local dealer. After quite a search they found some connectivity problems on the back of the fuse tray. I would probably never have found it. Thanks again for all the advice! Kind regards KC |
