Got my trans cooler setup together yesterday. It was a pretty straightforward operation all things considered. I'm happy with how it turned out, but I'm not sure if the fan is working or not. I haven't heard it engage at all, and I've tried to force it (stop and go traffic, driving through my neighborhood at 2000 rpm with my foot on the brake, etc). So I'll keep driving on it for a bit and see if I can hear it or see it working at all. If not, I'll start testing things. Make sure the fuse is not blown, check the relay. If all that is working properly I may need to look into the thermostatic switch. That's really the only part that worries me much. I can test it with some boiling water, so I'll try that. If it all works, I'll just not worry about hearing it.