Anyone know what the rating of the circuit breakers at the instrument panel on these old trucks is? I can find no marking on them or indication at the schematic.
TIA,
ray

 

One's 30amp and the other is 15amp.

The 30amp gets the battery power from the starter relay post through the ammeter. The 15amp gets power from the jumper on the two CBs.

The 30amp goes to the headlight switch, (dome light, door light switches if any), and stoplight switch and probably to the cigar lighter if equiped. The 15amp goes to the headlight switch also (different post).

Also, the 30amp jumpers power (not using the breaker) to the voltage regulator BAT, and the 15amp jumps it (not using the breaker) to the ignition switch.

I removed mine completely when I put in the fuse panel. They were then redundant.

 

Thanks, Joe. I also removed mine, complete wiring change out and 12 Volt conversion. I am considering re using the circuit breakers, one to feed the headlight relay power and the other to feed the cooling fan. I figured they were both about thirty amp.
1. Where and how did you determine one was a thirty amp and the other only a fifteen amp?
2. How did you determine which is which?

 

This diagram for the 49-50 will help. It's out of the Shop Manual on page 278.

And the 49 is different from the 51, so the routing is not the same. The 30amp gets power straight from the regulator and jumps it to the ammeter (without protecting it).

 

Many thanks, Joe. I did not have privy to that schematic with CB ratings listed. I guess I'll just have to buy a couple new CBs for my application. [I]Wanted to keep all the Ford I could[/I].
Reps given.

 

Ray, I think I kept my old CBs. Let me go look for them. If you want them, you can have them.


EDIT: I do have them, and the rating is marked on them. PM me if you want them.

 

No, no, no. A pair of new CBs is probably less than shipping. But, many thanks for the offer. This is what makes this forum so great, people helping people..

 

OK. I don't know why I kept them since I have no intention of ever using them on Betsy.

But they're perfectly fine, so I guess I couldn't just throw them away!

If you're converting to 12 volts, I doubt you'll need a 30amp.

 

RV stores sell them very cheaply compared to AutoZone et al. Much more variety of ratings too, from 15 to 50.