M37 battery box circuit breaker?

[ODAddict]

Without getting into all the "why's and wherefores," when dismantling my M37B1, I labeled a circuit breaker as a "battery box circuit breaker" as if it were installed on the box.

I'm aware that the breakers are supposed to be mounted on the cowl vent bracket, and I'm certain that the truck had one CB installed in that location.

Complicating the problem is that, while the holes on the CB line up with the holes on the cowl vent bracket, the #10 machine screws that I retained on the CB do not fit the holes in the bracket (the manual calls for #10 screws of the self-tapping variety, but the ones I saved are machine screws). To make matters worse, the holes on the CB line up perfectly with holes on the passenger seat base next to the holes for the seat latch as if the CB were installed inside and adjacent to the battery box.

While the truck came equipped with both the power plant and personnel gas heaters, I can find no reference in the applicable TMs to an included CB for these installations.

I can find only the one circuit breaker, but I'm beginning to doubt my sanity.

Help!

 

[G744]

I've seen the one in the battery box used for the radio power outlet in the bed front wall.

If I remember rightly, the two on the cowl bracket were for the horn and the dash-mounted outlet used with the corded trouble light found on the early models.

Lighting circuits were protected by the internal breaker in the light switch.

 

[ODAddict]

Mystery solved, sanity intact, memory maybe not so much. Now, why am I posting this? Let's see; oh, yeah. Back in my day....

Thank you very much to G744 for his response. He's dead on with his recall. In early models, there were 3 breakers installed on the cowl vent bracket: one for the horn, one for the light (intended for the M43 ambulance), and one for the light switch. Later models like the B1 had a single CB for the horn. As G744 said, the lights switch CB was incorporated in the light switch in later models.

Fortunately, I took lots of detailed photos even though they were not very well organized.

The photo below shows the CB mounted inside the passenger seat frame. This may be the subject of a future post.


The second photo shows the single CB (on my early M37B1) mounted on the cowl vent bracket.


But I still can't find this cowl vent CB. It's probably with the missing ignition power switch and handle.

 

[G744]

Those breakers were fairly standard across the tactical usages. 15A for #14 wire, 20A for #12 circuits.

They can be found is both Douglas & Packard connection formats from most MV parts houses.

 

[ODAddict]

In what can be described as nothing less than a masterpiece of organization, I found both the missing battery switch and cowl vent bracket circuit breaker. They were attached to the old wiring harness and stashed in another part of the barn (don't ask!). Mouse food? Here's a photo attached just in case someone is curious about the original wiring installation.



Thank you for the tip regarding the commonality of circuit breakers.