I have a twin p120 (old engines with 6.0+ ECU) in m A10. they have been great for two years.
I flew two flights saturday and then we got some rain. I covered the plane during the rain. Nothing was wet inside the fuse.
The turbines are well within the nacelles but only had a little if any water around the purple cowl.
I went to fly after that and one GSU had power without the Rx being on....it also displayed a temperature of (-)15C.
The voltage to that ECU was just a little lower than the load test I had done by handhels meter and the ECU was slightly warmer than the other one...

I unplugged everything and brought it home. I did not find much of anything but had the fan on the plane and turbine.nacelles overnight and this AM it was all ready OK..

So, do I chalk this up to some mositure that caused a temp short or is there a way to find out what caused the GSU/ECU to display output without the receiver being on?

Is there a way to test my ECU? I am getting the usual stratup chase sequence..

Thanks
Dave