Thanks Royce!
Yep, the engine was going, and by a while, I only mean about 1.30 mins for the fan to stop once we stopped on top of the hill, and it was going from about 1/3 of the way up the hill (about 200m long, maybe more - it took a while in 1st low!)
I can get a suitable diode from Dick Smiths I assume? I had forgotten that electcity flows in either direction
