behind the left hand park/tail light I have found an unconnected black earth wire. it's not the one for the fuel tank gauge or for the brake light, both of those are accounted for, rather another black earth wire and it emerges from the same bundle of wires which drive the park/brake/indicator lights but it simply stops there.

any clues as to what it earth?

 

Sorry, my stuff relates to an S3 car. Similar, but different. So, my comments are generic only.


1. Find a schematic for your car. One may exist in the archives on this forum. If not, expand your search.


2. An infamous aftermarket "manual", Haynes may be the source. Lifted from Jaguar publications, and containing difficult to read schematics that apply to your Better than none. In my book, not so much. Others think they are fine.


3. Use a VOM and see if they are "alive" or merely vestigial. The latter does occur!!


4. Do the circuits you name, work? If yes, let it be.


5. If the answer to 4. is "no, connect them to ground and see what comes alive.


6. CAVEAT, These circuits may be inoperable via "shorts" and a PO chose this method of disabling them. A real rank car full of worms.


7. If 4 is no, and it were my car, I'd prepare to remove the ground at the battery super fast, then connect them. I f Lucas smoke appears, remove the battery ground super fast.


Good luck with electrickery. I don't claim creation of the word, but admit to popularizing it.


Carl

 

Oh, way back when, I bought an after market electrical harness for the GM LT1
conversion. I wanted new wires. One branch of eyelet connectors was black denoting
ground (earth). I connect it that way. 0, nada in volts. Wrong, fusible link protected power source. Made the changes, everything came alive and the SBC fired right up. Off the "down pipes". No exhaust piping yet. Hard to beat the sound of an American V8 on open exhaust.


Carl

 

Do you still have marker lights?
(';')

 

check that you have license plate lights. Could also be for Rear Fog Guards used in Euopean and Australian cars, but not in America. Does the wire look broken-off or simply not connected??