b4 to b3 clock woes

[83mars]

just wondering if anyone could help me out,
i bought b4(i think) clocks with a rev counter for my b3,
the problem is the coolant light, with the old clocks it flashed for a bit and went out and stayed out,
but with the new clocks the light flashes 3 times goes out for around 10 seconds and comes back on flashing,
i tried the old clocks back in and its fine on that, its just happening on the new clocks,
anyone come across this??

i stripped down the clocks but couldnt see anything obviously wrong so put it back together,
any pointers would be appreciated.
cheers.