Wiring Issues

[Recovry4x4]

Todays order of the day is figuring out circuit breakers. I was studying the schematic and didn't find a circuit breaker for the headlights. The ones on the firewall are for the horn relay and the aux circuit. I ran out to the tractor and checked the wiring numbers on the breakers. Both were fed with wire 10. One breaker had wire 25 which is for the horn. The other had wire 37 which is unique to the tractor. It provides aux power to the semi trailers requiring 28V for interior lighting. This was exactly how the schematic shows it. Then I went to check out the pipeline. It had 25 on one breaker and 518 in the other breaker. 518 is for the flood lights on the pipeline. Accoording to the schematic, 518 is supposed to tie into 75 stoplight input. Oh well, its a little different. Then I decided to check out the front half of an M35A2 in the yard. It had wires 25 in one breaker and wires 74A and 74R in the other. According to my schematic, these are supposed to go to a fuel pressure switch. Do these fuel pressure switches look like circuit breakers and what is their purpose? Also, where is the headlight breaker? Maybe in the light switch?

 

[Recovry4x4]

OK cancel the questions on the fuel pressure switch. I just checked the -20 and now know all about the thing. For the record, its piped into the secondary/final fuel filter assy and not all of the M44A2 series have them. It's purpose is to keep from engaging the starter wen the truck is running. Still not sure about the headlight breaker. I'm considering Bjorn's idea of setting just the headlights up on a relay with an emrgency override.

 

[cranetruck]

The lights go through the light switch and the built-in breaker, which is 20 amps. See below for closeup image of breaker inside switch.

 

[Recovry4x4]

Thank you Bjorn. One day I'll figure these trucks out! Now, I wonder what kind of crap in in the pushbutton switch? I'm going to start shopping for a fried one so I can disect it.

 

[cranetruck]

This is what you'll find inside the new push button switch. All solid state.
Images courtesy of Tom Bauer. He sent me these some time ago.

Did you receive yours? I'm still curious about the brightness of the led's, like if they illuminate your face at night and make you look like some kind of ghost.

I now have all the parts for the head light bypass circuit, just need to get psyched up to install it.

 

[Recovry4x4]

Yeah Bjorn, I've got mine installed. It doesn't light you up at all. As a matter of fact, when the blue LED is on and you turn on the dash lights either bright or dark, it automatically dims the LEDs. I guess when they designed it they figured if you need dash lights, then it must be dark and they engineered the dim mode. The LEDs are behind the switch covers and they are translucent to disperse the direct light. Really its a pretty nead device. I've got $85 in mine but wouldn't really pay more than that. It's cool but not 3 digits cool!

 

[cranetruck]

You know, if you have a good working 3-lever switch, it can always be sold on ebay for 35-40 bucks and that will reduce the cost of the new switch too.
Of course, like with all the high tech stuff, best to keep a reliable spare around.
I like my paddle switches, wouldn't replace it if I got one of the push button ones for free. Just me, I guess.:banghead:
I have a special name for things that are very difficult or impossible to improve, "Prime Technology Items". Maybe a bit silly, but think about it, a lot of things just don't get any better. :yeah: :yeah:

 

[Recovry4x4]

It's a novelty item for sure. High tech means high problems most of the time. I've still got the takeout switch in case the preppy switch fails and still have one NOS 3 lever still in the box. I certainly won't put the preppy switch on my pipeline truck.

 

[rdixiemiller]

I'm definately into the K.I.S.S. truck. I could techify my deuce, but I like the simplicity. Some people do the opposite, and that is their privilege!
I guess I work with so much high tech stuff everyday that the simplicity of the deuce (and any old MV for that matter) is welcome relief. There is nothing like spending the whole day working on high tech broken things, then jumping in the simple old deuce, having it fire right up, and driving home.