I've never looked at the wiring diagram for a 48-50. But I'm pretty sure the battery power will go through the ammeter and then to the fuse panel main bus. I have a generator and don't know how to wire an alternator. If your alternator has a built-in regulator, maybe your statement would be correct.

I didn't use any fuses like yours. All my fuses are on the fuse panel. And I only needed seven. I don't think you have a dome light or door light switches, so that's even less fuses needed. You may only need 5 fuses, unless you plan to add accessories like a radio, heater, a/c, etc...

 

Correction to my last post..... The grey wire that runs through my ammeter comes from the solenoid and to the 15 amp circuit breaker. The red and black wire comes from my alt and powers the 30 amp cb.

The question is, which one is the power actually coming from. Once I confirm that then I assume I'd use that one to power my fuse box?

 

The battery power goes to the gray wire in your truck (#10 yellow on the wiring diagram). I believe that would be connected to the 30 amp circuit breaker. There is a jumper between the two circuit breakers, and the wire to the voltage regulator is connected to that battery power. Since you have an alternator, I can't advise you how to connect that, but if it's a 1-wire alternator, I think that would be your red wire with black stripe (#10 yellow on the wiring diagram).

So, to answer your question, the battery power to the fuse panel comes from your gray wire (#10 yellow on the wiring diagram) which runs through the ammeter.

Just so you know, the battery is providing the voltage normally before the engine is started (your gray wire). According to the wiring diagram, the generator (alternator) is tied into the same circuit and that wire (your red/black wire) is connected on the same terminal post on the CB assembly. As the battery voltage drops, the regulator senses the lower voltage, and the generator (alternator) voltage runs the truck. This continues until the regulator senses the high voltage and opens that circuit from the generator (alternator).

 

Thanks again for the reply Joe. The picture above is how the truck is currently wired (well before I tore it down for paint) and it was working with that setup. It matched my shop manual in the sense that the (in my case) grey wire comes from the solenoid to the 15 amp breaker and (in my case) the red/black comes from the alt (originally voltage reg) to the 30 amp breaker.



My latest question is; what would I do with the red/black wire that is coming from the alt if I used the grey wire from the solenoid to power the fuse box, or vise-a-verse?

 

The idea is, as Joe said, you use BOTH the alternator and the Battery wire to power the fuse block. With the battery wire routed thru the ammeter loop, the ammeter will then show the net flow to or from the battery (charging or discharging). You could run the ammeter output directly to the battery, but then the ammeter would only show how much current is being used by the loads in the truck, not the net. Not useful information.

If you used the alternator output ONLY to power the fuseblock, the truck would never start, because the alternator is putting out Zero until the engine is running.

 

I don't know if you can see in this picture, which is different from the first one I posted, but on the left side of the fuse panel, I actually have two wires running to the post on the fuse bus. One comes from the ammeter, the other goes to the generator BATT terminal.



To answer your question, they will be connected together. That's the way they were in your truck before. The solid metal plate between the two terminals of the circuit breakers is simply a metal jumper to short the two wires together. And I was looking at the large wiring diagram in the back of the Shop Manual when I said they would be on the same post on the CBs.

 

Light bulb! Consider me enlightened, thanks to the both of you! I guess I missed Joe mentioning before that both wires powered the fuse box. But I understand now and I have one on the way. While I have you guys on the hook what size fuses would you use for? That kind of brings it back to my original question. I believe the light switched would get a 30amp, but what about
Ignition
Brake lights
12v electric wiper motor (I think it may have an inline on it)
Dome light
Running lights
Turn signals
Radio (future)
Heater (future)
Did I miss any?
And lastly, since I have switched to 12v do I need to change the direction of the wire through the ammeter? I read conflicting/confusing info on it? In this photo I believe I have it run the original 6v pos ground route

according to the manual.

Thanks fellas,

 

Go look at your DD's fusebox, should be as close as anything for the proper fuse values.

 

Why didn't I think of that?! Thanks,

 

This is a great thread guys. All the info in layman's
terms. All good questions asked and answered. It should
be like a sticky that can be found easy for newbies.

 

Look at post #4. I gave you all the fuse ratings I have used. Since you're now 12 volts, there will be less amperage in each circuit. Half as much if my math is correct.

I believe you will need to run the ammeter wire the other way to make it indicate properly. Mine was in the stock position when I got the truck, but the PO had wired it negative ground, and the ammeter was pegging backwards.

Also, for your future electrical accessories, they should come with a fuse, or at least have an amperage rating so you know what size fuse to run.

 

That makes sense Joe. Now I did notice you had the ammeter listed with a 30 amp fuse. How will it have a fuse since it is one of the wires that will power the box after it runs through the gauge? I currently have a fusable link in the wire from the alt to the 30 amp circuit breaker, and I was going to put one on the wire from the solenoid through the ammeter and eventually ending at my fuse box, but if it's powering my box how will I fuse it with the fuse box? Did you install one of these between the solenoid and fuse box?

 

Yeah I know right? These guys are great, and I figure someone down the road will have the same questions as me. If it's spelled out in crayon then even I can figure it out. Thanks again felllas and let me know if you understand the question about the fuse on the wire that runs through the ammeter to the fuse box mentioned in post #4. Thanks

 

A properly sized fusible link will not blow unless something is really, really wrong. The fuses in the fusebox on individual circuits should blow first if the problem is in the circuit. The fusible links are to protect the very large wires feeding the fusebox. I'd guess your links for the battery and alternator will be rated around 150 amps. The links should be as close as possible to the power source (alternator or battery).

 

Thanks Ross! So the fusible link is all that's needed for the power sources. I did not previously know about putting them so close to the source (or I forgot). So can I start it right at the alt and Starter Solenoid?


It would be the one in the top left going to the fuse box.



And if I remember correctly you reccommend 2 sizes smaller than the main wire. So a #10 wire should have a #12 fusible link? I remember looking into this before and reading in that NAPA book about going 4 sizes, but it just doesn't sit that well with me.