Car won't start help

[needsabiggerfuse]

Have you checked the security of ALL the connections? I knew someone who had the same problem and it turned out to be a loose battery to chassis connection (at the chassis end). Movement of the engine at startup would sometimes make enough of a connection; but not at others. Total failure (on the way home from work - mid winter - pouring with rain) ensured some more detailed fault-finding than "It'll do a trip ...".