Rewired my 86 - now have security problem
 

Hi everybody.
I bought a flooded 86 and also a wrecked one. Just replaced all the interior wiring harnesses and a lot of the modules including the ECM. Went to turn it on and start it up and drive happily away and ..... nothing! The security light on the dash is flashing. I am using the original key. I am guessing I replaced a module that does not work with the key fob or something. Any ideas where to start?
Thanks. Brian.
BTW if you ever do this job plan on many hours stretched out on the floor of the car.