Spedo not working ?

[AdamDougal]

hey my speedo dosent work and im wondering what the problem could be? sometimes it works (iv noticed if i hit dashboard it come on for a bit or if a big base come on it might reset it)
but when iv asked people sposedly it runs on an ''electric pulse'' ?
any one got further details or advice please?

Cars a mk 1 T reg westcoast thanks.

[laberridge]

take out the clock surround, steering wheel and clocks, check for loose wires, cut/split wires, and maybe check the earth. also make sure all fuses are pushed in and working