Okay so I have the motor out of my truck now (1977) and am baffled at the purpose of a couple things under the hood. Specifically:



I'm know that the box with the fins on it ties into the alternator, but what purpose does it serve? The tiny piece with the one blue wire and cut wire can't really be doing anything as, well, theres only one wire on it. Also, the third piece with the two plugs on it.

To save questions later, I am swapping my distributor to a mid 80s non-points distributor.

Any help you guys can give me would be great. Ideally, I'd like to remove anything under the hood that I can so I get a cleaner look. Thanks in advance!

 

The bottom piece, the finned one is a diode type battery isolator, used for isolating and charging an auxillary battery such as in a motorhome application where you have dual batteries, the center item looks to be a circuit breaker, most likely wired to the isolator instead of an inline fuse, the top 2 wire box I,m not sure, its not stock, whats it wired to?

 

Thats kinda what I thought....thanks for the fast response. I'm assuming that the white wire thats attached to the isolator should go to the alternator then, right?

and the top box has 2 wires coming off it that go into the drivers side main harness that goes back through the firewall. I'll at least pull out that isolator and circuit breaker....thanks again!

 

Yeah, the white wire originally went to the alternator, its been cut and connected to the isolator, the blue wire coming from the isolator will be connected to the other end of the cut alternator wire, the other blue wire from the isolator goes to the circuit breaker and then went to the auxillary battery at one time.
Maybe a bigger picture of the top box might help in identifying what it is.

 

How about this?



I pulled the passenger side fender off tonight to tuck the wires on that side behind the fender. This looks like it's going to be the easiest vehicle in history to do a wire tuck on...

I'm hoping that whatever that top piece is winds up being something I can get rid of.

 

Thanks for the larger pic, I stand corrected since I can see it better, the white alternator wire wasn't cut as normally done, apparently why the isolator is mounted so low and close to the alternator. The top box still has me stumped, it kinda looks to maybe be a relay of sorts and the wires going to it almost look like the wires that went to the horn maybe.
Good luck with the tuck

 

You know, they DID have aftermarket horns in the truck. Maybe that's it. Once I get things put back together I'll test that out. THANKS!