Fans Problem On 999-fixed

Hi all
I hope this will be of some help should anyone encounter the same problem.
It all started in Germany. The bike stood two days in heavy rain and when the sun came out the
fan was running permanently when the ignition was on. Also the engine fault light was on. Strange thing was the dash said l/h fan fault but it was the r/h fan running.
Damp in the wiring seemed most likely and since it still ran ok the holiday continued.
Back in Blighty the problem persisted so I posted a question on here.
@chrisw responded with a view that it could be an ecu fault caused by electrical spike.
He suggested grounding the ecu through the diag port. Googling confirmed
that this often worked but alas not this time.
He then offered the loan of his diagnostic equipment which he duly sent.
This did not put the light out or stop the fan. So ecu failure was again mooted.
The fans are fed a + feed when the ignition is turned on, the ecu provides the - when it is told
the engine is at 102c thereby turning the fan on. So ecu failure is a distinct possibility.
Chris then sent an ecu to fit to eliminate or confirm failure in mine.
Alas this did not stop the fault but wasn't coded for my bike so we could,nt quite trust it.
No problem--- he just sent another virgin ecu.
This one worked with my bike perfectly but still the fan ran!
This is good news cos it eliminates expensive ecu replacement.
Now we have to check fan wire continuity. This involves identifying the correct pin sockets on the ecu plug, inserting paper clip and testing for continuity at the other end (superseal connector at fan).
The r/h fan tested ok (pretty obvious really as it was the one constantly running).
The l/h ground wire NO continuity, so bingo that's the problem.
Why a fault in l/h fan puts r/h fan on is beyond me.
Could it be safety system as l/h is the lower temp fan?
Anyway splice in new wire to piggy back old and job done. Cue huge wave of relief. Due to work and family commitments this whole thing took about two weeks and working in and around the battery box is a pain in the arse but the sense of achievement in fixing a problem like this is great.

NOW I have to say it would not have been possible without Chris.
A man I have never met sent me hundreds of pounds worth of parts and equipment.
He is a very clever, generous and all round nice guy we are fortunate to have him on this forum.

Hope this makes sense
Gary