Well , I think I’m closer than I was...because of other commitments I’m just dipping in 30 minutes at a time. Anyway it is winter in the UK, so time is on my side !
Here is an update on the slightly boring (multi platform) story of an annoying noise seemingly emanating from behind the box section on the bulkhead to which the bonnet catch is attached. Some of you may recall that the noise stops with the removal of a black wire running to the top LH fuse. That wire looks 'non original' being too new, too thick looking. This wire disappears behind said box section, but I have now found that it emerges from the other side, runs along the bulkhead, dives into the car on the LHD driver side and connects to the ignition switch. Interesting facts are: The car starts with this wire disconnected. The VR functions with this wire disconnected. All the cars electrical functions, lights, blowers, fans etc function with the wire disconnected. The noise is not coming from the coils, distributors, VR, or anything obviously useful to the operation of the car. So the temptation is to unplug and tape off the wire, never hear the still unexplained noise again, and move onto more interesting subjects. Yet, there is one note of caution. When I last started the car with the wire in place, I removed the wire while the engine was running (but still basically cold). The revs dropped instantly and the engine stalled. Whilst I was then able to re-start the car and nurse the engine up to temperature, it bothers me that the removal of the wire had a noticeable effect.
On the pictures below the wire is seen disconnected from the fuse box. It runs seemingly un-broken from there, behind the box section pictured, and to the ignition. The noise measured by Db meter and stethoscope seems to come from behind that box. The wire when jiggled at the fusebox end moves at the drivers end before it disappears behind the water bag on its way to the ignition. Therefore it is unlikely that it runs from the fuse, to some hidden device behind the box and thence the ignition. It seems a single wire from ignition to fuse. I will now remove the box section to verify this and have a poke around. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
could it be that the ignition eletric switch not works right an dso the black wire is more a jumper wire? disconnet the wire and checkt he voltage at the coils 15, may be you only get there 7 volts or so? meassure before the resistor but now I wonder a little: I see from the resistor there goes a red wire to ignition coil - ( minus ) an dfrom the other side of teh resistor a black wire to ignition coil B+ ( so 15 ). I wonder how this will work?? or does the phot not shows all realy good? please make a photo that I can see what wire comes from where and goes to where
Hi Joe, do these pictures help ? Is 15 a reference to the wiring diagram in the manual “Dynamo Regulator” ? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
those are the same photos as you have postet already only now larger and I still can not see right the conenctions. may be you reomove the high voltage cables from the coils? and make a photo from the top of the coils to see clearly where is + (plus) and - (minus) 15 is coming from the main igniton switch. 30 is from the battery to the main ignition switch and from there it is going on with 15 to the coils. on the first photo the coil for the left cylinder bank when I see it right on the photo it says B + on the coil showing to the right ( so left side in driving direction ). there it should come on 15, but not directly. 15 goes from the ignition switch to the resistor ( the white/rustbrown square ceramic ) and from this resistor to B+ at the coil. the wire from the distributor goes to - ( minus ), also called 1 at the coil. and the condenser ( the little black square, is only for lower radio frequency ) is also going to -. so as I see it it is not all connected right? important is that the wire from the points in the distruibutor will go to - ( minus ) at the coil, not to + (plus )
here you see how it works. sorry, only written in german but I think you understand the working oif the system? the kondensator (condencer ) in this gif is this one in your distributor and not this small black one outside the coils. Image Unavailable, Please Login
Hey Joe, Here are some more pictures of the coils from above, one with the high voltage cable removed. To me everything seems to be wired up correctly. I ran the car again today with the black wire un-connected every thing worked just fine. Although I understand the system in your great graphic above I feel I have gone as far as I can. The car is heading off to Terry Hoyle for some other work on Thursday. He knows a good classic electrician. Time to hand it over to the professionals. I will, of course let you know, what they discover. Image Unavailable, Please Login Image Unavailable, Please Login
thank you for the greaat detailed photos graham so you see that the red wire from the resistor goes to coil 1 ( minus ). so the other wire to the resistor ( black one ) comes from the points in the distributor or from ignition switch (15)? can you please make a sketch from where the black wire you mentioned goe from to where? I know it goes from the fuse box, but where goes the other end?
Hey Joe, the mystery black wire simply runs from the fuse box along the front of the Bulkhead then though the bulkhead under where the washer water bag is located to the ignition switch. Or more, correctly starts from the ignition switch and runs to the fuse. Unfortunately the ignition switch doesn’t come out easily when you turn the knurled chrome ring so I can’t yet see the back of the switch. The black wires to the resistor vanishes into a hole in a box section below the box section on which the bonnet catch is mounted (see below) Where it goes from there and what lies behind that box I do not know. I will point my electrician in that direction. Image Unavailable, Please Login
Possible, the wire does look different from the rest of the stock wiring. Maybe it is some legacy anti theft device making the noise.
As the transport guy, who was supposed to pick the car up today, just let me down I will do some more metering later today.
Exciting news ! I have discovered an after market toggle switch cleverly hidden well away beneath the dash. When you switch it from its current position the annoying noise stops. The car still starts and runs. All that happens is that the noise stops, exactly as if I had unplugged the black wire. I think then that those of you who deduced that the issue could be related to an aftermarket anti theft device may well be right. I am treating the case as “closed”. Thank you all ! Hopefully I will buy everybody a beer at Pebble Beach....
Got it ! Re-visited this and finally got it. It seems so simple now ! The under dash toggle switch operates an after-market electric pump for the screen wash. It was partially hidden by the fluid bag. That is the source of the noise. Will replace it or live without. Thanks to all those who offered help and suggestions. Image Unavailable, Please Login
Hey Joe, at a guess I had knocked the toggle switch with a knee and it was trying to pump, but getting no water. You can see the pipe has come adrift, leading to internal issues.