1974 DS23 automatic electrical issues
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  1. #1
    Fellow Frogger!
    Join Date
    Dec 2010

    Default 1974 DS23 automatic electrical issues

    I recently de-hibernated my DS23 and amongst other things, replaced the original Ducellier alternator with an ex-VN Holden Commodore Bosch internally regulated unit. The Bosch unit is working well, but while doing this work I have created / identified some further issues.


    1. Referring to the attached image (DS Repair Manual 814-part 1 – wiring – DBW issues):

    a. The ignition key has recently become ineffective in starting the engine

    i. Note: 2.4v ‘start’ output read at starter inhibitor switch

    b. The ‘ignition’ function seems to work alright

    c. I have temporarily connected a Momentary switch (only connects while pressed, mimicking the key start operation) at the red sleeved wiring junction (key start feed) located near the battery.

    i. As expected:

    1. operating this switch turns the motor over irrespective of whether the ignition is on or not.

    2. the motor won’t turn over if the gear selector is not in P or N

    ii. The motor runs normally if the ignition is also switched on at the key.

    d. I would appreciate any suggested remedies for the apparently low voltage supply from the key start.

    2. During this recent work, I found that the ‘New Era’ (model 591?) starter solenoid had also ‘expired

    i. (I suspect the original starter solenoid fitted to my car (carby, not fuel injected) was installed on the +ve battery terminal, as shown in the 814 circuit diagram.)

    ii. I have replaced the New-Era solenoid with a Fuelmiser CS51 unit, which I am told is a ‘Ford-type’ solenoid similar to the ‘expired’ New-Era solenoid, so I have wired it similarly (see attached images):

    1. Ignition wire to ‘S’ terminal; and

    a. (ignore yellow lead – now disconnected)

    2. Loop from Battery +ve terminal to ‘I’ terminal (on solenoid).

    a. Can anyone suggest whether this connection (2) is correct and if so, what purpose the connection serves?

    3. During this work, I have re-acquainted myself with the wiring and related functions in the vicinity of the battery, but some of the following components remain a mystery (see attached image 3):

    a. SANOR Relay located next to SANOR auxiliary fan relay; connections:

    i. Yellow – coil +ve

    ii. White – earth (near coil)

    iii. Black – terminal block (circuit breaker? alongside relay – see image 3)

    iv. Fourth terminal – no connection

    b. Item next to above relay (circuit breaker?); connections:

    i. Battery +ve

    ii. Above relay (terminal 3)

    c. Main harness bundle: Blue wire – female termination (blue sheath) – not connected to anything: see image 3

    d. Any clarification of these queries would be much appreciated.


    Attached Thumbnails Attached Thumbnails 1974 DS23 automatic electrical issues-fuelmiser-cs51-ford-type-starter-solenoid-labelled..jpg   1974 DS23 automatic electrical issues-new-era-starter-solenoid..jpg   1974 DS23 automatic electrical issues-unknown-components-near-battery-1974-ds23-carby-auto..jpg  
    Attached Files Attached Files

  2. #2
    Fellow Frogger!
    Join Date
    Apr 2016
    Bedford, UK


    I don't know if this is any help, ad you are probably way ahead of me but.....

    if a combination of the ignition key turned and your extra momentary switch enable the car to start, then it all points to the one of two switches in the ignition unit that switch that completes the circuit to the coil. the switch that provides current to the coil works fine. EDITED: I can now see there are three connections in the ignition unit. There is an in line fuse but not in the circuit to the starter. Points to a dirty or broken contact in the ignition unit perhaps? Switch cleaner?

    Relay: a relay with only three connections isn't going to do much! Black and white connections are for the battery and 'load'. Yellow and mauve are usually for the power to the trigger or switch. The wiring you have described suggests that the relay is set up to provide a heavy current to the terminal block(?) from the battery, that one side of the 'trigger' circuit is connected to a power supply (the coil) and that what is absent is the wire from some kind of 'switch' or primer for the relay? Following this wobbly logic, the switch would need to be something that you relied on operating to then provide a big current to the terminal block? Doesn't make sense to me! Where does the terminal block lead to? Is it possible that the relay and terminal block are some kind of crude starter solenoid? Either before or related to your 'new era' thing?

  3. #3
    Fellow Frogger
    Join Date
    Jan 2004


    It's very hard to see your pictures, but I can almost see what's going on.

    I assume the starter originally worked via a solenoid on the +ve battery terminal in this car. That was intended to work by providing the earth side of the starter solenoid via the ignition switch. Where it is deleted and the starter motor had 2 wires going to it, +12V is fed down the line via the starter switch instead. To do this behind the dash there is an extra flying lead taking +12V to the switch. See if the lead that comes from the starter switch is open circuit when off and then leads to earth or +12V when you move it to the start position. It's possible the control side of the solenoid is currently wired with both sides to earth.

    Those green Sanor relays are for the AC system, when fitted. One is an AC system control relay and the other cascades from it to run the blower in the under-dash unit and or the condenser fans. All the terminal should be connected. There are separate accessory diagrams for the AC wiring, but you really just have to make sure the control relay is switched via the under-dash unit and that it cascades to the second relay.

    I'm not sure if the blue wire coming out of the harness is associated with it, but there are a few pigtails in that area that connect to the oil switch, extra cooling fan, temp sensor and the starter (solenoid or lead to the starter). See which of those is and isn't connected. I don't think it will be where the brake pad sensors plug in.
    Last edited by David S; 4th October 2017 at 08:17 PM.

  4. #4
    Fellow Frogger!
    Join Date
    Dec 2010


    Thank you, Budge and David S for your responses.

    I will delve into your responses in due course, but I thought it worthwhile responding at this stage to confirm that the car did have air conditioning when I bought it. I removed that equipment because I didn't like the concept of the huge York compressor being driven by the camshaft. Also, it's very much a car which is driven when conditions are suitable; i.e. not in hot weather.

    I also attach slightly larger versions of the two images with text superimposed.

    Attached Thumbnails Attached Thumbnails 1974 DS23 automatic electrical issues-unknown-components-near-battery-1974-ds23-carby-auto-44.jpg   1974 DS23 automatic electrical issues-fuelmiser-cs51-ford-type-starter-solenoid-labelled.jpg  

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