have fitted my rebuilt cossie lump this weekend, and am having a little trouble with the running temps, also i fitted a new temp sender for the gauge.

basically the gauge moves up to just above the 'O' , and the fans still haven't kicked in and when driving along,the gauge is around the 'O' still??

what i'm thinking is maybe i've been given the wrong temp sender,and the gauge is reading too high, i don't want to leave it running for any longer than i have been though, in case it is over heating.

the fans come on when i bridge the wires.

so either....

A: the temp sender is wrong,and it's over reading and i'm not letting it run long enough for the fans to cut in...
B: the sensor for the fans is duff,and they aren't coming on, but why would the gauge be on the 'O' whilst driving,when it always used to sit half way (i haven't changed thermostat)

does anyone know any voltage checks i can do on the sender?