Hi Malachy,
a typical indicator/flasher relay should have 3 connectors numbered:
- 49 (lightgreen (LG) cable from hazard switch)
- 49a (lightgreen/brown to indicator, hazard)
- 31 (black - earth/ground).
See the following diagram for a 1990 car
https://franks4x4-morgantechnical.blogspot.com/2019/11/other-morgan-wiring-diagrams.html(A power relay will have 4 or 5 connector, numbered 30,87,87a, 85 & 86 - I assume that this is one you have under the bonnet.)
On my 1984 Morgan I had an older flasher with two connectors (49 and 49a) - ground was directly done because it was attached with the screw to the bulkhead just behind the steering wheel.
Just try to follow the LG cable from the Hazard switch.
Careful: lightgreen is also used in BSAU7 standard cabling for Voltage Stabilizer to gauges (eg. fuel & temp)
Do see this in the 1990 wiring diagram... but who knows.
Hope this helps
Regards
Tim