Engine doesn't start every so often. 420A

[nairb_sd]

Okay, before work today me and my friend stopped by the gas station. Got stuff, got in the car, and it wouldn't start. I tryed to push start it 'cause I was late for work. I had to bang on the positive wire coming off the battery to get it to start. Could corrosion prevent connectivity? or the wire isn't tight enough to the terminal. any help pls. thanks

 

[luv2rallye]

yes both battery cable connections must be clean, tight, and not corroded. Remove them, clean (wire brush) the cable connectors (and especially on the inside with sandpaper), clean the battery posts (wire brush), and put back on tight (tighten bolt that holds them onto post). To prevent corrosion, now smear vasalene (or grease) all over them.