Defender Td5 intermittent engine light

So after many a dark night in the shed messing with my 90 iv managed to find the fault that had me tearing my hair out lol

Started with no check engine or coil plus no prime, so checked the usual suspects, fuses, inertia wiring, ect

Turns out I had one slightly green cable under my fuse box which showed continuity but high distance under load.

Luck would have it I lent on the fuse box top a the main relay clicked an clatterd.

She’s now working, (for now at least )

Looks like it was short lived problems back an left me scratching my head again,

Sounds a little bit like a problem I had around a year ago. The fault was a break in the wire that goes from the inertia switch to the relay under the driver's seat. When the ignition goes on, this sends power via the inertia switch that then switches on the relay which them provides power to the ECU. I bridged the load terminals of the relay with one of my partner's hair clips and the dash lights came on and the engine started.

The ECU has some permanent lives, plus around three (as I remember) which are powered via the relay, so when it's not working you get some functions but not others. So no glow plug light or engine light, and the engine doesn't start.

I'm not saying that's your problem, but it's worth a try.