No coolant stains.

And how would coolant get all the way to ecu unit when it's behind where stereo is. But u hav checked and it has no markings on it as auto electrician has left it out of car. He did not put things back together. He seems to think there are 2 positive connection when he said should be 1 positive and 1 negative. But me totally confused.
Cheers.

Heater core has coolant running through it and it happens to live just above your ecu and stereo, so when heater core leaks......Seen it happen before. But since there is no coolant on ecu problem is elsewhere.Good luck cheers

Oh true. Learn something new every day cheers rs2000. I would never had guessed that. That's the blonde comin out lol. Thanks heaps for ur help but.

Well if what the sparky said is true, looks like there must be a short in the wiring loom somewhere.  You could try unwrapping the loom and checking it yourself while the car is pulled apart anyway
 

The electrician took the wirin loom. Said he is goin to look at it in his own time free as I told him I have no more money to do any more. If it is damage in wirin loom does that damage the computer at all. Cheers Phoenix 13918

It possibly could yes.  Depends on what has shorted out to what.
Nick