I have a 1990 740 non turbo, rex/regina igition.
It died the other day while running.
There was no spark.
The battery light remained on with the key off or removed!
I traced the short to the wiring harness behind the alternator.
Three wires were crossed: the hot lead from the alternator, the small red one from the alternator (hence the battery light) and a green wire that I believe runs to the coolant temperature sensor. I repaired the cables.
Still no spark.
The crank sensor has been replaced and I have ruled out the fuel pump relay and the radio suppression relay.
On board diagnostics gives me 1-2-3 and 2-2-3.
Coolant temp sensor and idle air control valve.
It should get spark.
What gives?

Thanks

Richam