Was going to convert some round fuses to blade type fuses today, I have the adapters, have the fuses, etc. I know my truck is doing OK, but the blade fuses are easier to store / read / swap out. Lately I've responded to a few working on their fuses, etc ..... and I noticed somethings weren't adding up. I'll replace like amp fuses with like amp fuses, one by one just changing style, but I found this to be odd just the same. Below are copies of both page 127 and 128 of my owners manual .... you know ... the book you carry in the truck to refer to at zero dark thirty as you attempt to replace that fuse trying to get you some lights back on while out in that blizzard on the side of the old 50 west of Holcomb, Kansas?



Or am I missing something?

 

I thobk that the orientation of the fuse block in the owners manual and in the actual truck is different and or maybe wrong. Also might be a early year 77 and have some different lay out? Note the position of the phillips head screws, top LH and lower right.




Now the screws are top R/H and lower LH.

Early 73-76? Maybe early 77 to mid 77, then a change?


Owners manual free download.....again. https://drive.google.com/file/d/0B9Y...J_jpVdqy9XQf6A

 

Mine as it came in my '77 here. If there is a 3 amp fuse in that spot, I'll put one back ... or if it's a 7.5, I'll do the same thing. Part of why I was looking so close to these is I have two taps added, and I think I put them on the hot side of the fuse, not the fused side .... but it's been so long ago I forget. I can probe each side after I pop the glass fuse out, the side I want will be hot (not fused) and then I'll know. I might have done that 30 years ago?

That white thing hanging down has nothing to do with fuses, it is just a zip tie with a bent end. That chunk of fuse box was missing since I can recall .... my guess is someone was prying a fuse out.

 

My '77 is dated 03/77 on the door jamb sticker.

My post above with the charts, etc is from the 1977 owners manual that I have. The fuse box depicted is like mine as you can see. I thought was the pre '77 that had a smaller fuse box, but maybe was very early '77s too? I used to carry a 1979 owners manual that I took out of a donor as I had none ... then I stumbled upon the 1977 owners manual that is in the truck now. Today I got to thinking, the obvious conflicts in the 1977 book might have been corrected by 1979 printing in that the book .... so I looked. The '79 book shows (pgs 152 & 153) that #2 illumination circuit as having a 3 amp fuse in both charts, and the heater / ac is listed in both charts too, but they did raise that fuse to a 35 amp. I also see that both charts in the 1979 book agree that the aux Tank Solenoid is 7.5 amps and both charts agree on the number of fuses. I updated my 1977 book.

Might be there was even other revisions in '77 and editors missed some items. It can be confusing because so far as I see, each book has two separate fuse charts.
I'm not overly concerned with it, but the conflicts did fuel my curiosity.

I wouldn't mind having an unblemished fuse box, with no missing parts, but it's been like that for 40 years anyway, so I'm not sure it's something worth swapping out now? I could use J B Weld and something like greased pop sickle sticks to build a form and fill it.

I thank you again.

 

I have enough to adapt 9 but am thinking I may just adapt 7. The one (#3) for aux. tank solenoid , the one (#4) for seat belt buzzer, and the one(#5) for throttle solenoid ... though present, can just stay as glass fuses as I don't have any of them and they are up on the top row. Two spaces (#6 and #7) are blank in my box. That leaves me adapting #1, #2, #7, #8, #10, #11, #12. I'll include spades for present extra wires as seen now (at #2 & #7)


These seven should do it. Lower box is a Ford box, but is not label like a F-150 would be.
Fuses shown may or may not be correct color / amperage rating, is just illustrative. Yellow circles highlight where two wires are tapped in.

 

I wonder if highboys kept the old 5-fuse panel from the earlier years?
That would explain why both are shown in the book.
The aftermarket books all show the 10-fuse panels as being from ‘75 on (or is it the 5-fuse in ‘76?), but it had obviously changed around that time.
As for the different orientation, dunno. Anyone have a van around that vintage? Maybe the different orientation was for different vehicles and got mixed up in translation.

 

My ‘78 is the 12 fuse block, with the #1 slot empty of hardware. It was vertical in orientation and mounted to the kick panel. It also had factory A/C and the blower switch was off a 35amp. I still run the original fan and resistor set up, and can confirm a 30 amp will blow.

Your best bet is to run what it needs, not what the book calls for. Also keep in mind your harness, fuse block, and all the splices are as old as the truck. Unless it’s been stored in a heated garage its entire life, corrosion will be at least a slight concern.

For now just run what’s printed on the fuse block, or if unsure go with the smaller size suggested and keep a lot of extras of all sizes until you’re sure. I keep an ammo can full of fuses, splices, wires, relays, etc just in case. Have but typically don’t need.

If you want more over share info on wiring or lighteningy thingys, let me know. I’m not much of a DC guy, but Oregon seems to think I’m qualified for that kooky AC sine wave stuff.

 

Kick panel? You think was mounted there OEM?
Yeah, I knew in '78 / '79 the heat /AC called for 35a, don't know what was different from a '77, mine says 30a but I don't recall what's in it. I added the actual AC in the '80s after stripping two wrecks and adding a few new items.
You don't by chance have a picture of the back side do you?

 

It appears that was the original mount location, but somebody had added a brake controller, CB etc several decades ago, so anything is possible.

Bottom is bottom, top is top, left in picture is Right side from the front.

Let me know if you want more info, as in wire colors and associated numbers for ‘78.

 

Thank you Sir, I was looking for a picture that showed me the buss bars, and it does that.