Hey all,
My name is Adam from Reno, NV and I've been lurking around the forum for about a year, this is a great site.

I'm starting my first Ford build and need some help identifying some electrical components.

I've got a 77 F250 Highboy that originally had a 351M but now has a 460. There are two electrical boxes on the driver side firewall that I have NO IDEA what they are.

They look like voltage regulators and are wired together along with some sort of thing that looks like a starter relay but is missing one terminal. The actual voltage regulator is near the horn so I don't know what these are. They say 12V "switch" on them so maybe they're some relay? The truck had a winch at one time and dual batteries which have been removed. I traced the 4 wires from them and they go through the firewall and up the drivers side window post into the headliner/roof?!? Crazy. This truck was used for search and rescue at one point. Any help identifying these would be great!

 

Here's a pic of the mystery duo…

 

And because I teased the title with some build pics, here's what I'm working with-
77 F250 Highboy bought from my wife's mom. The step dad was the first owner and he passed away from cancer a few years ago so it sat on the farm for awhile. It has sentimental value for her side of the family so it'll be cool for them to see it back in action.
He had a stock '72 460 in it that was converted from a 351W.





















I'm only on the engine build right now and it's my first one.
D3VE ported and polished heads, 3 angle valve job, new valves and springs
Crane hydraulic cam and lifters with new rods
New timing set straight up
Stealth intake with custom built Holley and recurved dizzy
L&L headers

It's my first engine build and I'm breaking it in on Tues with the guy that did my heads but I'm still a little nervous!
After she's up and running, I'll head down for dual exhaust then over the next year I plan to do suspension, body/paint, then interior.
I really love these Highboys how they look stock from the factory so I'm just going to re-arch my springs to level it out and stick some 35s on it. It should sit and sound nice!

 

Where there any holes in the roof to the outside? The truck may have had a light bar, if not possibly some overhead radios

 

It's got an extra CB antenna on the rear driver's side window post that's no longer in use. The head liner was replaced at some point so I don't see anything there or on the outside. It has the standard dome light and switch and it also has rear brake light on the outside above the rear slider window.

Radios make sense because he did search and rescue and it's got that CB antenna built in. Does that stuff need relays/switches or anything like that?

I forgot to mention that I took the covers off any they are definitely relays, there are two solenoid coils in each along with two fuses...

 

Definitely something aftermarket. My guess would be relays for off road lights or something like that.
If it were mine, I would just get rid of it all.
If the dual batteries were the factory setup then that solenoid that's missing a terminal was for that.
In the stock setup the auxiliary battery was used to power a camper. The solenoid disconnected the second battery from the electrical system when the ignition was turned off so you wouldn't run the main battery down. When the engine was started, the solenoid would reconnect the battery to the electrical system so the battery would recharge.

 

Mike's on to something there!
The wires going up to the head liner were most likely a radio installed by the PO. I've seen lots of weird things done like this. SAR is volunteer so it's make due with what you got

 

Thanks, guys. I think you're right, it's got to be aftermarket, I want to get rid of it and I've already got it wired for one battery right now. I just want to make sure if I take it out, I'm not eliminating something another circuit may need.

Thanks!
Adam

 

Nice truck, good job on the engine!

 

I'm confident that you're good to go eliminating all of that extra wiring.

 

Thanks, Mike. I'll know for sure on Tues!

Thanks, Blackjack. Still a lot of work to go!

 

That winch and brush guard are ugly as hell, probably worth nothing more than scrap metal!!









I can come over and unbolt it and take it to the scrap yard for you, prolly get u $100.😉

 

Jkl, sorry for the late reply but if you want to come to reno, it's already unbolted you can pick it up! Bring a friend though because it weighs about 300 lbs.

 

Wow! Thanks, Mike, for the excellent explanation of that wierd second solenoid. I was just wondering about that on my truck.

David

 

Here's the illustration of the dual battery from the Ford parts catalog.