Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Started to work on another NSX from this week.
The service menu is to carry out the Health Check, refresh the cooling system, replace the faulty FCU (Fan Control Unit), etc.


The owner already informed me that his coolant header tank has cracked and leaking.
I use specific procedure on installing the tank and addition to the batch/quality issue of the tank itself, there seemed to be another common factor for owners experiencing the crack.
It's how the car was parked after driven, mainly the thermal shock.


So, on arrival, started with the general check up before the test driving although it was so wet and windy for a few days that I decided not to go out for the test driving session and just carried on with the Health Check.


One thing that I just couldn’t stand was the faulty FCU.
It was triggering the a/c condenser fan (and rad fan from time to time) even when the CCU was completely switched off (and even when the engine was cold).
Typical soldering crack at the circuit board. Same failure mode as the Main Relay.






So, opened up the existing FCU and sure enough, several cracks were found at the connector area as well as on many components.






Re-soldered it and will be returned to the owner so that it can be used an emergency spare.



I knew Honda (or should I say the parts manufacture) did change the soldering method for the Main Relay so the new ones from recent years have better life expectancy but not sure about the FCU so opened the new one as well.




Unfortunately, I didn’t like the way it was soldered and also being as basic single sided non-through hole type non-glassfibre circuit board, I’m quite sure it will fail again so decided to re-solder it as well despite being a new parts.




New but re-soldered one installed and now there is no more faulty operation of the a/c condenser fan or the rad fan.




By the way, the fuse for the L side condenser fan was blown so replaced it.



Had to stop here for dealing with Japan and will continue with the Health Check.


Kaz