Stickfinger wrote: ↑Tue Mar 02, 2021 7:18 am
Not yet, next job on the list....
To diagnose this you ideally want three bits of equipment:
Standard test lamp,
High wattage test lamp (headlamp bulb),
Jumper wire.
There is no starter relay fitted to Xm, the full starter solenoid current passes through the Ign switch to the starter.
There is a Start Inhibit relay fitted to automatic cars, so the starter only operates in P, or N.
The relay is a remote switch so the the high starter current doesn't need to pass through the gearbox selector switch.
To diagnose quickly, split the circuits by locating the starter inhibit relay, pull it from the socket and perform a visual inspection of the relay and sockets. Leave the relay out of the socket.
There are two thin gauge wires and two thick gauge ones.
With Ign off, use the standard test lamp between Battery +ve and the thick cables to find which is the feed from the Ign and which feeds the starter. The starter solenoid coil will provide a Gnd connection and illuminate the lamp.
Use the jumper wire from the Battery +ve to the contact to trigger the starter.
If this works you can be confident that part of the circuit is sound. Move on.
Use the high wattage test lamp between Battery Gnd and the other thick cable, then turn the Ign key to START, while observing the lamp.
If it illuminates that circuit is sound.
Use the jumper wire between the thicker gauge Ign switch contact and Starter solenoid contact, ensure the gearbox is in P or N, then turn the key to START.
If the starter operates, the high power circuit is all good. Remove the jumper cable and move on.
Ign off and the gear selector NOT in P or N.
Use the standard test lamp on the thinner gauge cables to find the Gnd. (Batt +ve to connector)
Test with high wattage lamp to be sure of good continuity and load carrying capacity.
If the lamp illuminates it is sound.
With Ign on, connect the standard test lamp between the final thinner gauge wire and Batt Gnd and observe as you move the selector lever through the range. It should illuminate when the lever is in P or N and be off at all other selections.
If this test fails, check for power input to the switch and other outputs...dashboard display and reverse lamps. (observe).
If all the above tests are passed, the fault has to be the relay, which I believe you have already changed.
You can compare your findings to the wiring diagram for familiarity and if further diagnosis is required...e.g. Fuse numbers, connection points.
