Led Flashers

[jp928]

Put LEDs in the turn indicators, bought a LED flasher can, supposed to be adjustable. Fitted it - flash quite slow. Tried to adjust it, no change. Tried too much, adjuster thing fell out of can. Put the original Bosch can back in place...still the same slow flash rate. Usually LEDs make flashers go fast, as the low load looks like a failed bulb to the flasher..? The cans are 2 pin type, labelled B (battery) and L (load).
Any ideas please?
thanks