Land Rover Repair: 98 Disco Ser I 4.0 AT Starting Problem, spark plug wires, condenser fans

Question
62K miles on the car. One of the A/C condenser fans was burned out. I replaced it (now it works) but I had sent 12V current back thru the harness both at the temp sensor and the fan motor not realizing it could damage electronic components.

At this point the car barely starts, runs very rough, lots of smoke, very rich exhaust.

Next I ran an OBD2 (Its a scanner that can read the data even though there is no trouble light on: Actron 9145) scan. No trouble light, no errors on the scan. However the coolant temp showed -40 degrees and the Air intake temp was 18. I replaced the coolant sensor. Nothing changed. I replaced the ECU with a salvage unit. Now an OBD2 scan still shows no errors. However the coolant temp and air intake temp now show the ambient temp so that is good. But the car won't start at all. It tries to fire every so often on exended cranking.

Next I plan to replace the Main/Fuel Relay. After that I don't have ideas. Any suggestions?

I have new spark plug wires on order but don't think they are the problem.

Answer
the more info i have is better but with electrical it is very difficult its never cut and dry.check all fuses.under dash & hood.the look thru wiring diagram to see were the wire you put 12v goes to possible computor burned out and generic testers cant read it.alsosee if you can run thru system check and see what the o'2 sensors are reading.it would be good start.if not check for some 1 knowledgable with land rovers in your area.
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