'79 Bronco starting issue

[valleau]

I've tried everything I can think of and need some other ideas.

Issue: '79 Bronco with a 400 and C6. Son has been driving and just wouldn't start the other day after school. I tried to jump start and it threw sparks from the alternator.

Alternator and voltage regulator were replaced and still no start. So far I have replaced battery, starter solenoid, and starter. As long as there is no load (i.e not connected to new starter) everything operates and functions as it should. Once the starter is connected, the entire electrical system goes out. I've removed the starter and tested on the bench and it checks out fine.

Any suggestions would be very welcome.

 

[valleau]

Also I have changed the terminal cables and cleaned the connections.

 

[Seabronc]

Also I have changed the terminal cables and cleaned the connections.

Welcome to the Zone >

By terminal cables, do you mean the one from the starter to the solenoid? If not, you probably have a rub through on the insulation. Use your meter to do a continuity check of the (+) line with the battery disconnected. If you see a short, start disconnecting components until it goes away.

Good luck,

>-

 

[valleau]

Thanks for the info, cabling ohmed out good. Ended up being the block connection to the starter. Read another thread where somebody suggested running a separate ground from the starter bolt to the frame, and it worked. Thanks again.