I have a rather old A/B refrigeration unit on my boat, and while it seems to be working well enough.....the fan never shuts off. I mean NEVER! I recently had to replace the fan since it gave up the ghost. Put a new one on that I got from A/B. It seemed like it shut off a few times, but now it doesn't. I checked the control module and its a sealed board with no options for repair. The module on the unit is not the original....in fact it looks relatively new. How long should one of these modules last? Is there anything short of replacing the module? Thanks!