Wiring Diagram for 91 Dynasty (3.3 litre)

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).

Chris

 

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.