Got a '72 Bronco. When I try to start it up, I get a very rapid ticking noise from under the hood and that's it, the engine won't even try to start. I installed a new battery, a new starter silenoid, a new voltage regulator, and a new fuel pump. Do I need a new starter, alternator or what? Thanks for any help.

 

That rapid ticking is almost always the starter solenoid, and it almost always means that there is insufficient current to turn the motor over. But, since you have replaced the battery and starter solenoid:

a) is the battery fully charged? Have you tested to verify that it was fully charged or put a charger on it?

b) Do you have a bad or corroded battery cable? Any looseness or corrosion in the battery terminals can seriously reduce current output.

c) Check the positive connection on the starter to make sure it is clean and tight and that the cable end is not coming apart. Also, check the negative cable attachment point on the engine for the same thing.

 

I'd go with the cable theory if you've replaced all the major components. Happened to me.