You have a connection missing!
Everything is as it should be but there should be TWO connections to the positive terminal - one to provide a dedicated high current path to the starter - a big fat cable - and a slightly smaller one for the vehicle electrics.
Without that connection the only thing that gets power is the starter motor relay.
Search out the missing cable and connect it up.
I know nothing of vehicle maintenance.
Good Luck...
April 2016
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