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This is on my new 1966 F350 project. I'm not the most knowledgeable when it comes to wiring, still learning. The piece is located on the inner fender, passengers side, in the engine bay. I'm thinking it's a ground bar/strap, but it's made of layered material and it seems fibrous. Or it's metal that has become extremely brittle. Possibly not a ground, but some type of insulated connector/junction? The red wire is not connected here, it was simply run underneath the broken piece in question; it goes to the horn. Sorry, lots of wires were sprayed over in black (not my doing) and I should probably gently clean them up for better color identification.
Also, what is the small box that's nearby the broken piece in question?
Throwing out a guess and see if it sticks; the 2 heavy gauge wires appear to me to be a junction block for the 'alt' gauge? The black box appears similar to the horn relay? Be interesting to find what more knowledgeable member's have to say??
Posting diag. from 1965 Ford F100-F750 Wiring Manual. Purchased the manual thru Jim Osborn Reproductions for $7 plus s/h.
Thanks so much for the input, Dave. I believe you are correct on both. After searching google a bit about your guess on a "junction block," I came up with some very similar pieces like this:
Throwing out a guess and see if it sticks; the 2 heavy gauge wires appear to me to be a junction block for the 'alt' gauge? The black box appears similar to the horn relay? Be interesting to find what more knowledgeable member's have to say??
Posting diag. from 1965 Ford F100-F750 Wiring Manual. Purchased the manual thru Jim Osborn Reproductions for $7 plus s/h.
I won't go as far as to say I am one of the more knowledgeable members, but I have spent enough time under the hood of our trucks to know daveengelson is correct on both counts.
A few words of caution.
I have found over the years that the factory wiring diagrams may show parts and pieces that aren't always there, such as the circuit breaker shown below the starter solenoid and the diagrams may also omit some of the wiring for certain options.
Use the factory diagrams as a guide, not as the gospel.
Fix that immediately or disconnect the battery until you do. If it hits the inner fender and grounds out the results won't be pretty..
Agh thanks..I was actually just researching more about it and read just that! Geez, I can't believe disaster hasn't already struck, I was fiddling with it just last night. I'll be disconnecting the battery terminal as soon as I get home, until I can make the repair.
Originally Posted by Roger Carter
I won't go as far as to say I am one of the more knowledgeable members, but I have spent enough time under the hood of our trucks to know daveengelson is correct on both counts.
A few words of caution.
I have found over the years that the factory wiring diagrams may show parts and pieces that aren't always there, such as the circuit breaker shown below the starter solenoid and the diagrams may also omit some of the wiring for certain options.
Use the factory diagrams as a guide, not as the gospel.
Hope this helps.
Thanks for the input. Certainly wouldn't help much chasing ghosts!
Just to tie this up for any future reference, I'll be going with a fused junction block just to be safe. Something similar to what Dave used here https://www.ford-trucks.com/forums/1...n-block-2.html, shown in the picture below. Going to the parts store for a few items after work anyway, so I'll pick one up and get this taken care of.
The picture actually shows a circuit breaker. Regardless of name it will work for you application.
Be aware that all the electricity your truck uses will flow through your new circuit breaker. Make certain it has adequate capacity. The factory wiring diagram shows a 70 amp breaker. That would be a good starting point.
The picture actually shows a circuit breaker. Regardless of name it will work for you application.
Be aware that all the electricity your truck uses will flow through your new circuit breaker. Make certain it has adequate capacity. The factory wiring diagram shows a 70 amp breaker. That would be a good starting point.
Good luck.
After reviewing the wiring diagram I originally installed a 60 amp fuse block, this was many years ago and the 'alt' gauge worked fine. Purchased the replacement fuse block a few weeks ago and the sales person suggested going with a lower amp fuse explaining he was of the opinion if a fuse failed at 25 amps it would likely be less damaging to a circuit than at 70 amp. Not having a clue on the subject figured I would give it a try, so far, the 'alt' gauge works fine. Having said that, there appear to be 2-3 ways to run the Alternator Gauge circuit and strongly suggest the owner should make sure the circuit they install is appropriate for their application.
After reviewing the wiring diagram I originally installed a 60 amp fuse block, this was many years ago and the 'alt' gauge worked fine. Purchased the replacement fuse block a few weeks ago and the sales person suggested going with a lower amp fuse explaining he was of the opinion if a fuse failed at 25 amps it would likely be less damaging to a circuit than at 70 amp. Not having a clue on the subject figured I would give it a try, so far, the 'alt' gauge works fine. Having said that, there appear to be 2-3 ways to run the Alternator Gauge circuit and strongly suggest the owner should make sure the circuit they install is appropriate for their application.
Granted, the lower the ampacity fuse, or breaker, you can run, the safer the circuit will be. However, using a breaker or fuse with too low a trip point will create its own set of problems, mainly nuisance tripping. The higher rating allows for some safety factor, should the alternator give out.
When all is good with the battery and charging system the ammeter should read near "0". The alternator is handling the needs of the truck and the battery is just along for the ride. If the alternator should fail the battery would have to pick up the electrical loads and the ammeter would show a strong (-) discharge. If this happened on the infamous dark and stormy night when you were cruising down the road and had your high beams on, defroster fan on high, radio cranked up, etc., it is a pretty safe bet the 25 amp breaker would trip, leaving you in total darkness. At least until the breaker cooled and reset. The factory shows a large breaker to prevent this from happening.
The ammeter will work just fine regardless of the fuse or breaker rating, as long as the electricity flows. In some ways fuses, circuit breakers and ammeters are similar, in that they measure the amount of electricity that is flowing. They just respond differently when their max limit is reached.
For the ammeters on our trucks there is only one way to wire them so they give accurate readings. To do this ALL electricity the truck uses, or generates, must the ability to flow through the ammeter, with the exception of the power to the starter. That is why the factory wiring for the ammeter was so large.
If only some of the power routes through the ammeter the reading will not be accurate. Using a headlight relay kit with its own fuse and direct battery feed would be an example of this.
Like with any subject there are variables and what ifs that can be tossed out. I have tried to offer a basic explanation.
Roger; thank you, information greatly appreciated. As I mentioned, not an authority on the subject, not that it would make a difference, but the alternator gauge circuit on both of my 65's is some what different than what is shown in the wiring diag., either way, I figure if the alternator fails I am punked. Information certainly offers food for thought, intend looking into it further; meantime, keep a watch with any issues that surface in the circuit. Again, thank you!!
Seems the thread got a bit off the OP's original question. Hope we were able to answer his questions without adding confusion to the mix.
Not a problem, extra details help get a better grasp on the whole picture. Especially for newer guys like me, still learning. I got the answer(s) I needed, thanks guys.
