73 CS Electrical advise sought

Discussion in 'E9 New Member Introductions' started by pickman, Jan 28, 2019.

  1. pickman

    pickman Member

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    As a result of my restoration the body was stripped and the wire harness completely re taped. In the process of installing the rear lights and have issues. Using a battery charger to power appears if the battery is isolated it will charge when hooked to the cables it will turn off. Also when I can get it to stay on - turn the ignition key and check the turn signals, emergency lights, run lights, brake the instrument lights go off and only very dim light on the rear bulbs.

    I do not have the entire electrical system hooked up working from back to front. I can hear what sounds like contractors clicking under the dash when I move the under dash wires.

    Not all the wire colors match the electrical schematic from my manual.

    In short need some good advice as this will be time consuming and I do not want to damage any components.

    I was wondering if the voltage regulator may be faulty?
     
  2. Simufly

    Simufly Active Member

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    Unlikely. The voltage regulator regulates the output of the alternator, nothing else. Check ALL the connections for corrosion.
     
  3. pickman

    pickman Member

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    I think there is a wire shorted under the dash somewhere as, while using the new battery charger, sometimes the power just shuts off to the ignition key.
     
  4. jmackro

    jmackro Well-Known Member

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    I don't fully understand the symptoms outlined in your first message. What is it that "shuts off"? The battery charger? If yes, then I guess it may be detecting an over-current condition, caused by a short, and shutting itself off.

    You may have multiple issues. For example if only the rear lights are dim, that could well be a bad ground(s). Bad grounds are common after a car has been painted. But a bad ground wouldn't cause the battery charger to shut off (if that is what is shutting off).
     
  5. pickman

    pickman Member

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    Thanks for your reply. I am not sure what's going on yet. I cannot start the car where I am working on it so can rely only on battery and battery charger power. I did clean the netal wher the grounds are attached but will re-check with my fluke meter for impedance. The only lights connected are the two rear tail lights, my wiring diagram has a wrong color wire on the RH schematic vs. the in car wires.

    I turn the ignition key on and the fuel light comes on and the oil light (bright) I pull the light switch out and they go off - the rear tail light (including side markers) are barely visible very dim. The LH and RH turn light seem OK (bright) but the indicatiors on the dash do not light up. Again I have not all the switches and lights connected.

    I was poking around under the steering wheel and can confirm there is something (which sounds like) a short and hear relays clicking.

    I got my schematic out of the Blue book - I have both the blue and whits manuals. Looking for advice as to:

    Will the system function properly with only partial connected switches and lights?

    What to look for under dash?

    It appears the rear lights are pulling too many amps when the light switch is activated.
     
  6. jmackro

    jmackro Well-Known Member

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    Diagnosing something like this over the internet is pretty much impossible. I certainly don't know what's going on.

    Do you have all the fuses installed? If it were me, I would start with NO fuses and first try to get the ignition, load shed relay, starter and any other non-fused components to work. Once that was done, I would add one fuse at a time, and ensure that each circuit was working.

    A few other ideas:

    - I would be concerned that the color codes of your wires don't correspond to your wiring diagram (are you confident it's the right diagram?). On my 1970 2800CS and Prospero's Garage diagram, they correspond quite well (but that's just a sample size of one; have others had this experience?). Are you sure that your harness wasn't re-taped so the wire that was supposed to connect to the windshield wiper motor now goes to the turn signal flasher (or whatever)?

    What does a short sound like? I usually smell them (e.g., melting insulation).

    I don't know what you mean by "partial connected". Each circuit (e.g., fuse) is independent, so as long as all the headlight (say) components are fully installed and correctly wired, the headlights will work OK without the windshield wiper (say) components being installed/connected. Was that your question?
     
    Last edited: Jan 29, 2019
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  7. rodspock

    rodspock Member

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  8. rodspock

    rodspock Member

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    I had similarly strange electrical issues when recommissioning my E9 - indicator switch would make the alternator light flash etc.

    It turned out to be two identical plugs under the dash that were connected to the wrong way around into the car loom.....

    There are two identical 12 pin (from memory) plugs under the dash - one comes from the steering column and the other comes from the instrument binacle. Find them and then check if the wire colouring is consistent where they connect the car loom.

    If the wire colouring across the plug is not consistent then swap the plugs to main loom connections.

    I think this will solve your problem.

    Cheers,

    Rod
    (Brisbane, Australia)
     
  9. Wes

    Wes Active Member Site Donor $

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    I had a similar problem on my 72 CS. The plugs for the indicator stork can actually be connected upside down.
    This meant I could flick on hi-beam and the horn would go, indicators wouldn't work etc..
    Drove me mad figuring it out as it's not a cause for a fault you'd expect.
     
  10. Rek

    Rek Active Member

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    It worked when it was built so you have something connected wrongly or a component which is faulty.

    Is the ignition switch OK? If it is triggering the load shedding relay then strange things can happen as I believe it reduces power in favour of the starter motor, and it clicks loudly.

    I happened to stumble upon a wiring diagram where the colours matched the ones on my car. There are a few wiring diagrams out there. Here is the one I used.
     

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  11. Ohmess

    Ohmess I wanna DRIVE! Site Donor

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    I had a ton of electrical problems with my car when I first obtained it. Jmakro's suggestion of pulling the fuses and working upstream from there is a good one. When looking at the upstream circuits, remember that some of them are wired together at the fuse block. This is not very well illustrated in the wiring diagrams.

    Looking at fuses 4 and 5 on this fuse block, for example, shows the connection at the top of the block across the two terminals. Indeed, every wire attached to the terminals in the plain red area will be connected. This effectively acts as a distribution block built into the fuse block. And this means everything upstream of fuses 4 and 5 is wired together. The plain green area behind fuses 6 and 7 functions the same way.


    Fuse Block.jpeg
     
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