Wiring Diagram for 91 Dynasty (3.3 litre)

Discussion in 'General Motoring' started by C. Bailey, Oct 21, 2003.

  1. C. Bailey

    C. Bailey Guest

    Does anyone know of a wiring diagram for the above on the web? I am trying
    to figure out why the speed signal wire (attached to the speedometer in the
    instrument cluster) gets extra voltage when I put my lights on high beam.
    It alternates from 0 to over 5 volts. Without high beams, it alternates
    from 0 to around 3 or 3.8 volts. The result is sometimes my speedometer
    will not work unless the high beams are on, and on other occasions, it will
    not work unless they are on. I have a new speed pickup on the transaxle.

    Does the signal from this wire go straight to the ECM, or does it go to the
    speedometer? I have noticed some weird things with my high beam indicator
    light (bulb good, but no voltage seems to get to it). I'm thinking it may
    have a short somehow to the speed circuit, but I have no idea what circuitry
    they have in common (if any).

    C. Bailey, Oct 21, 2003
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  2. C. Bailey


    Aug 26, 2022
    Likes Received:
    On my 92 Lebaron the speed/distance sensor wire goes to the PCM and the instrument cluster. The speed sensor has 8 segments which are either ground or open, as the car is in motion. This provides the signal for the PCM and the speedometer. A voltage surge burned a resistor and several guage illumination lamps in my instrument cluster. The resistor is part of the circuit providing 12 volts and 5 volts to various circuits, temperature guage, battery voltage guage, etc. This could be similar to what is happening with you.
    silverchevy, Aug 26, 2022
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