No fuse box on this truck??!!

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NAM VET
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No fuse box on this truck??!!

Post by NAM VET »

Yesterday, was working on front side marker light, and found with a test lamp that it was a bad ground. Fixed that, works great now. But I managed to touch the center electrode in the bulb's socket with a screwdriver, and had a momentary 24 volt spark. After a few impolite words, I was sure I had shorted that circuit's fuse, and was surprised to find the four marker lights were fine.

Then, got to thinking, something that occasionally has caused me no end of trouble, and realized that the only fuses I knew of on my truck where the one I put in for my electric fuel pump, rewired horn, and re-done turn signals. So, is there a fuse box somewhere I just haven't noted yet? I just can't imagine the havoc a 24V short would do with the old wiring and abrasions on these trucks. Mine has a new wiring harness, and in my rebuild I made sure all the wiring I came across was protected in various ways.

I just can't believe a vehicle would be made with no fused protection for the circuits. But I sure don't know where it is?

NV
NAM VET
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Re: No fuse box on this truck??!!

Post by NAM VET »

Was just reading old posts via the search, and understand that my truck has circuit breakers on some lines, and not others. Someone in an old post suggested this so blown lines to some non-mission essential items won't deadline the truck. Also lots of warnings last dated in 2016 about cracked and defective "grommets" in Douglas connectors. My truck has both Douglas and Packard connectors. I had to pull a lot of them when I removed my motor, and if the referenced "grommet" is the rubber insulator over the wire inside the Douglas shell, they all seemed to be OK. The prior owner put in a new "NATO" harness about 15 years ago. When I got my truck, it came with all sorts of spares, and bags of Douglas and Packard parts, and rolls of Military 14 ga wire. It all looks OK to me. So I think I get it now. And electrical things look ok. My repaint the other day is what caused the running light ground to fail. By the way, very happy with my second respray.

Drove out to a rural gun range Sat, where we had an IDPA shoot. I did fine, and got lots of questions and interest about my truck. When I was ready to leave, there were railroad ties in front of me, to keep cars from rolling down a hill, so I just drove right over them to turn around. These big tires make easy work of obstacles.

My 1919A4 30 CAL is being delivered today. I'll post some images in a few days. Taking one grandson to Disney later this week. Running down to Charleston tomorrow. Just lots of things going on.

Now, for Coffee and a Danish. My mom's mom came over via Ellis Island as a 15 year old girl, from Norway, so a Danish pastry is pretty close for me.

All well here,

NV
just me
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Re: No fuse box on this truck??!!

Post by just me »

Horn has its own circuit breaker.
Lighting has a breaker.
Ignition does not.
If so equipped, the instrument panel has a breaker mounted on the back for the instruments. Some vehicles do not have this.
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rickf
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Re: No fuse box on this truck??!!

Post by rickf »

Doesn't mean you cannot put one in. The military would just replace the vehicle if it burned down, no big deal. A little different scenario for us. I plan to source some extra breakers and put them in all of the main lines.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
PoW
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Re: No fuse box on this truck??!!

Post by PoW »

The individual G741 breakers are usually mounted on the brace from dash to firewall, where the vent lever is.

Most of the master lighting switches are internally protected, early ones had one external.

All necessary circuits are protected in the stock configuration.

A serious short will trip one immediately.

Unfortunately, the addition of tactical turnsignal hardware results in burnouts of lever and/or flasher before the breaker trips if any of those circuits go to ground. (usually from faulty trailer wiring) :(

PoW
NAM VET
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Re: No fuse box on this truck??!!

Post by NAM VET »

makes sense, maybe that is why my military turn signal system was non-functional when I got my truck 18 months ago. I was not capable of finding where the fault was, so just removed all of it, the box on the floor, and the signal arm on the steering column. I opened up the box, and it looked fine inside, no rust, so maybe the problem was in the lever arm. I kept the box, tossed the arm. When I pull out of my driveway, I and flick on my turnsignal to turn right, it is reassuring to know that my self-restored electrical circuits are working just fine. I am still in the "post-personal-rebuild" reassurance mode with my own M37. Maybe driving a near near 70 year old truck, one I have spent so many hundreds of hours restoring, will always give me some subtle anxiety that I did it right, and it is now dependable for my own driving. Looking at my aftermarket oil pressure gage and seeing the same oil pressure I have now 600 miles post re-build just makes me feel that the machine shop and I did my engine right.

Thanks for the update.

NV
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Re: No fuse box on this truck??!!

Post by Kaegi »

u don't want to blow a fuse in a war machine. breakers will click if there is a short and keep trying to send power and may keep you running down the road when getting shot at . same as aircraft. a bad connection is better than none when flying. ;/)
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