Cooling fan hookup?

[sluggie24]

I hooked it up to the BEC output wire and it seems to be ok.....although the speed control isn't hooked to the motor yet. Since this is the first time I powered up the system I noticed that the steering servo seems to pulse/twitch when no steering input is being given, even when the wheels are off the ground. I disconnected the fan and the twitch did not change. The shift servo does not do it. I have an Airtronics MX-3XS controller and reciever and an Airtronics ERG-VB high torque steering servo. Does anyone have any idea what this might be caused by? The BEC is all the way in the back of the truck as far away as possible. I tried moving it around with no affect. Radio interference maybe? I was inside by the entertainment center.