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post #1 of 53 (permalink) Old 09-08-2019, 04:48 PM Thread Starter
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silver shadow spaghetti

Hi I recently bought a 1976 Silver shadow, which runs well but has a ignition light that likes to be on all the time unless the engine is running, it has a CAV Alternator and has a new regulator box but the same fault is present, also with the Key out of the ignition the radio, seats, wipers and drivers window all work, just wondering if anyone else has come across this problem, started to check through the wiring but its a bit like spaghetti ! lol
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post #2 of 53 (permalink) Old 09-11-2019, 10:56 AM
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Martyn,


Well the spaghetti approach did not get any reaction.


I still think you should do the fuse pull test and remove each one to see if the supply to that gen light is coming from any fuseboard supply circuit or direct from battery circuit unfused.


Also did you fit a CAV regulator would like to see a picture of what you have there in the engine bay.


Also probably need to check each wire has been placed correctly even if you just did like for like change it needs to be checked someone else did not misplace a wire.


Keep the post updated as you do things.


All the best


Steve
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post #3 of 53 (permalink) Old 09-11-2019, 04:31 PM Thread Starter
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Hi Steve, I have now removed all the fuses in the "fuse box", the light is still on, a friend tonight suggested that I take off the Alternator feed wire to see if the light then goes off, he works on heavy goods vehicles and said that is what he would try next.
the nights are drawing in now so will have to leave it to the weekend to try something else
regards
Martyn
Attached Images
File Type: jpg alternator rr.jpg (55.3 KB, 9 views)
File Type: jpg cav regulator.jpg (51.3 KB, 9 views)
File Type: jpg RR regulator.jpg (54.6 KB, 11 views)
 
post #4 of 53 (permalink) Old 09-12-2019, 01:40 AM
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Hi Martyn,


I agree, my next steps would be to remove the Brown/yellow wire at the regulator see what happens, then remove the brown/blue wire again at the regulator box.


The key now is to find what puts that light out then focus in on where that line circuit and how it could be picking up a permanent supply.


All the best


Steve
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post #5 of 53 (permalink) Old 09-12-2019, 04:02 PM Thread Starter
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Hi Steve,
if I remove the WL wire , the light goes out, but stays out when the ignition is on, sorry I don't do colours, do you know which terminal these wires go too? will do more investigation Saturday, and keep you posted
Martyn
post #6 of 53 (permalink) Old 09-13-2019, 02:19 AM
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Martyn,


I don't see a WL wire. Is this a marking stamped on the regulator somewhere. The print on the schematics can sometimes be a bit blurred on the wire ID.



Take a picture of the area it may show up the colours or mark up the wire you are removing as that will be a good starting point now.


Not an easy area or subject I accept for someone who is colour blind. At least the schematics are in black and white.


I will be around over the weekend. Did you get my email address and home number.


Steve
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post #7 of 53 (permalink) Old 09-13-2019, 03:55 AM
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Martyn,


OK found the WL (I think) it is very blurred on the schematics I have but it is the markings on the regulator box casting.


The brown/yellow wire here is direct to one side of the gen warning light so that is good the light now goes out. The schematics show two Brown/yellow wires on the drawing connected here. Not sure if these are crimped together or just linked on separate terminals. Can you confirm as it may need each one removed separately to trace a fault. You might need to be diving in behind the regulator to the thermal delay and choke solenoid circuit and this is a pain to get at.


Next connection to it on the regulator is marked A and is Brown/blue. Leaving the Brown/yellow WL wire connected now remove the Brown/blue wire and see what happens to the gen light with ignition key in OFF position.




Its beginning to look maybe like a duff diode in the alternator. Possibly a good clean down at alternator connections would be a good start at the weekend.


Regards


Steve

Last edited by Steve E; 09-13-2019 at 04:04 AM.
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post #8 of 53 (permalink) Old 09-13-2019, 08:16 AM
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Martyn,


I am going to dive in here feet first and give you something to look at.


The two brown/yellow wires at the regulator WL are linked either crimped together or linked at the Lucar connectors on the regulator.


One wire is direct to the gen warning light the other goes to the cintilla thermal delay switch which energises the choke solenoid to keep the carb induction flap closed on initial cranking. The choke solenoid when energised on initial crank will not actually pick up and hold the flap unless you go through the procedure of pressing the accelerator pedal down before cranking. Choke will stll work as that comes off the manual choke coil which is heat related from the exhaust manifold.


That aside.... it is quite possible you have a fault inside the cintilla thermal switch as these are a problem......I have lots of faulty ones but have not found a suitable repair method yet. See the picture below.....Jean7 if you are reading this.... one day I will. I have been able to repair some when it has just been oxydised contacts and the elements and insulation good.


My thoughts here are maybe the element wire has broken (which they do), and making contact with the bi-metal blade or the insulation on the blades has broken down (which it does). As there is an earth circuit on the thermal blades if the element has broken away or insulation rotted through you may be getting a circuit through the gen light that is keeping it alight.


Just something for bedtime reading and following the schematic before you start at the weekend to get your head around.


What I would do is (ignition OFF) and the brown/yellow wires removed is test the wire and see if it does go to earth. If the brown/yellow wires are separate then you can test each one individually disconnected from the regulator. If the light goes out with the choke thermal switch disconnected then for sure this is now where to start looking. Unfortunately the thermal switch is tucked under the metal housing with a lot of other relays. I can see you have speed control which makes it even harder to get to.



Do the quick wiring check and see what the results are and let me know.


Regards


Steve
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Last edited by Steve E; 09-13-2019 at 08:20 AM.
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post #9 of 53 (permalink) Old 09-13-2019, 02:58 PM Thread Starter
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Hi Steve,
head is spinning already,lol, have just pulled off wire A (Brown Blue? two wires in one connector.) the light is out all the time, so does not come on with ignition in either ACC or On. wipers and seats still work with ignition off. checked for current with all wires fitted to regulator, WL (brown Yellow?Two wires) 2.36 volts, A (brown Blue, two wires) 2.36 volts, Black wire - sign .01 volts, F Brown Green single wire 0.82 volts and Hi (Brown single wire) 12.37 volts this is with the ignition in the off position. Med and low terminals there are no connections. not sure where to find the item in your thumbnail, are they plastic or ceramic? I have three ceramic discs on the inner wing near the air conditioning sight glass next to the radiator.
regards
Martyn
post #10 of 53 (permalink) Old 09-13-2019, 03:39 PM
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Martyn,


Let me digest the information. All those volt readings need analysing but I don't really take much notice of volt readings on a multimeter they can be spurious and give false impressions.The items on the front wing are just the fan speed resistors so nothing to do with the problem.


The thermal choke cut out as I have pictured above is hidden as is about 10 Lucas relays under the metal housing that the regulator sits on. Even worse there is a printed circuit board which gets contaminated.


Time for a rethink though if the seats and everything (accessories wise) works with these wires disconnected and key off.


I will put up some pictures tomorrow what is underneath the blower motor and behind the regulator just for your reference.


Thinking now this is either some serious screw up behind the fuse board as you said it looked like tampering or just a simple problem with the ignition key switchbox problems.


I see you have fog lights now from the garage pics and a vinyl/everflex roof. Does your switchbox have a 'FOG' position as these were an accessory. If aftermarket usually the switchbox has not been changed so does not work the fog lights or have the decal......


And I thought I was going to get a good nights sleep tonight


Will be around at home at the weekend


Steve
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