the number of times I come on here to piss and moan about my car I should probably
a) give it a name out of courtesy
b) get the mods to stiky it!!
Anyway, for the last few months its been a none starter, well sometimes anyway. Turn key ignition light comes on (i.e. everything working, but alternator not spinning yet), turn one notch further, light goes out, but nothing else happens 
Assume that it's a dodgy solenoid (it's only intermittent), so I check it this morning, starts first time, "ahh well" says I, I've got the part now, I'll be done in time to get to the shops to buy some bacon for a lunchtime sarnie.
Does it work now, does it f***!!! Ignition light now comes on, and stays on through the entire process. Checked all the connections, checked there's a voltage getting to the solenoid, there's a voltage through the solenoid, there's even a voltage at the coil where (AFAIK) the starter solenoid earth's itself (oddly, onto the +ve terminal, presumably this is +ve when the engine is running and as a results makes sure the solenoid is firmly shut).
Grrrrrrrrrrrrrrrrrrr, can't figure it out. Must have nudged something with my elbow while fitting the new solenoid, most likely somewhere between the solenoid and its earth, but can for the life of me figure out what.
