I thought I would just post this. I have a Cyclamatic Power Plus which started cutting out, the motor would groan or growl and wouldn't pull the bike. Sometimes it would work fine, and the problem re-occur. In my case I found that the external shrink wrapped connector between the rear motor drive and the controller housing, was the issue. Having read that people have problems dismantling this, I thought about going about this differently. Firstly, to sort of prove it was the connector, I carefully unclipped the cable from the frame, placed the connector section on a soft wooden block, and 'gently' tapped it with a hammer. The motor immediately came to life. So the issue is that there is a deterioration of the contacts in the connector, causing the circuit to be intermittent. Tapping it regained the circuits, but I decided it may still fail again unpredictably. After this I opened the ends a bit of the shrink wrap, and blasted air through it, as I am fortunate to have an air compressor, but a tin of compressed air should do it. I then sprayed Servisol contact/switch cleaner through the whole assembly hoping this would revitalise the contacts. When finished I tested it and tied tie wraps around each end to reduce the ingress of further dust. It has worked fine since.