Tesco hopper crank sensor problem.

[iankw]

Hi I'm new to this forum. I'm trying to resolve a problem with the crank sensor on my Teco hopper.
The central part which fits over the crank became loose due to some of the splines breaking. I searched for a replacement but could not find the exact same type which has 6 magnets. In addition the fixed sensor was also worn due to rubbing of the magnetic part which had broken.
Searching on ebay I found an 8 magnet item with a sensor and subsequently ordered that thinking that the extra 2 sensors would kick the motor in a bit sooner. When the item arrived I tried just to change the magnet wheel and use the original sensor as the connecting plugs were a bit different. This did not work so I then changed the fixed sensor and joined the new wires to the old plugs by connector block. This still did not work.
I then noticed that the wheels with the magnets on were attracted to each others magnetic field. So I replaced the old sensor and then fitted the 2 wheel components to the crank with the broken one being held in position by the new one. I now have partial success. When i start to pedal the motor kicks in for a short time say 30 seconds or so and then stops. If I carry on pedalling the motor will kick in after a short time and then stop again. Has anybody any ideas or can inform me of where I can get the correct 6 magnet crank and fixed sensor? Thanking you in anticipation.

 

[vfr400]

You lost me completely in the last paragraph. All pedal sensors work the same. It makes no difference how many magnets they have. There are three things you have to get right:
1. The wires have to be connected in the rght sequence - red to red, black to black and signal to signal.
2. The magnet disc has to be the right way up, otherwise it will work only when you pedal backwards.
3. The gap between the disc and sensor needs to be around 1mm.

Always test that it's working before you put the crank arm back on to save yourself a lot of work.

 

[iankw]

Hi, Thanks for your reply. The original wires were Red black and green. The new sensor wires were red blue and yellow.
I had the bike upside down and tried the pedals in both deirections with no effect on the motor at all using just the new disk and sensor. The gap is approx 1mm

When I put the old fixed sensor back on and reconnected the original wires, and put the new and old disk together onto the crank with the new disk being used to hold the old disk central with the old disk closest to the sensor. The motor kicked in. I then took it for a test ride and that is when the intermittent motor problem arose.

Maybe I connected the new sensor incorrectly. I put red to red, black to blue and green to yellow.

 

[vfr400]

You probably connected it incorrectly. When the wires are red blue and yellow, yellow is often ground, other times blue can be ground. No harm will come if you connect them the wrong way, so if one way doesn't work, try the other.

 

[iankw]

OK will try this later. Thanks for you help.

 

[Nealh]

Try Black to Yellow, Red to Red & Blue to Green.

 

[Fat Rat]

Hi welcome