I am posting this so the information might be findable on the internet by the few people with cars with radiators who might be interested.
I have an Intermeccanica 356 D convertible with an Audi 1.8t engine. I have had an issue with the two-speed radiator fan. Once it goes to high speed, it doesn't shut off while driving.
Took a while to debug the issue. The fan controller is a Spal pwn v3. I was able to find the manual online. Controller has three settings. It isn't possible to see what it is set at, only possible to reset it. I think it was set to the first setting (a LOW temp of 170° (low speed fan) and a HIGH temp of 185° (high speed fan)). It was challenging to find the normal operating temp of the 1.8t online. From googling around it seems to be about 90C (194F). That would explain why it never turned off once it came on. Set it to the second setting (low at 190 and high at 205). For the first time since I have had the car the high speed fan turned off while driving after it had turned on.
