3 Lever History

[Barrman]

This is a dual purpose question. It will help with my 1952 M35 work and I just want to know.

What vehicles first used the 3 lever switch? Do they all have the power to the blinker circuit built in?

I ask because my Gasser switch looks the same and has the same number of pins out the back as a modern one. Yet, the M35's didn't have blinkers when they first came out. The military was still trying to make the single tail light/single brake light on the drivers side with the b/o stuff on the passenger side idea work.

Did someone design the switch with that much anticipation or did they just get lucky that it had enough pins to work a blinker system?

Thanks.

 

[maddawg308]

I think the first vehicles to use it were around 1950/51, the M38 being the 1/4-ton model, the M37 being the 3/4-ton model, and the M135/211 being the 2-1/2-ton model.

 

[cranetruck]

The turn signal action is all external to the 3-lever switch, it only "takes the power" from it.

 

[Barrman]

Pins J and C go to the blinker system. I imagine that C which goes to wire #22 was the orginal brake light "out" to the rear. What was pin J for? It goes to wire A if you have the old relay blinker system and turns into wire 460/461 for the solid state systems.

I guess I should have asked that first. Was the 3 lever designed with blinker systems in mind but not yet implemented on any current production vehicles at the time? That would explain pin J and the power going out it when ever the service light side of the switch is used.

 

[acetomatoco]

I was probably just an auxiliary wire which could be used for any purpose... The really early 3 lever switches had two harnesses and two plugs to them... Front and Rear truck harnesses...came together at the switch...you see them in the early M135, M37 and M38 manuals.. Some of them had 12Volt gauges with resistors in the harness, too...

 

[gwalker]

Yes the orignal 3 way switch was designed as part of the army's new (in1950) standardized electrical system, which was intended to make all manner of electrical parts an wire numbering common to all mil vehicles, and requiring them to be waterproof. The first design switch had two wiring connections on it the main harness and the other was just for the trailer plug harness.(or the entire rear harness I dont remember ) It was quickly redesigned to a single conn. since having the seperate connector served no useful purpose. Although in the beginning t/s werent used they must have made consideration for it by having the extra pins in the switch connector.. The m-880 was the first mil vehicle to be built that no longer was required to adhere to the mil standard electrical system.

 

[cranetruck]

Re: RE: 3 Lever History

.......The m-880 was the first mil vehicle to be built that no longer was required to adhere to the mil standard electrical system.

Very interesting....yeah, I mean it it's interesting, David Doyle could probably add some insight to this....

 

[DDoyle]

RE: Re: RE: 3 Lever History

The origin of the three lever light switch goes back to WWII, and a starter/ignition switch, as shown below in a T26E3 Pershing tank.

The light switch goes back to 1948/1949. The first Reo (M34) ran in 1949, well ahead of GMC's M135/M211. But I believe the M38 Jeep preceded the M34, as the M38 is listed in a July 1949 supply catalog.

Several years ago I did an item on 24 Volt electrical systems for Army Motors - which I'll have to dig up - but I recall that work on this had begun during WWII.

The taillight/turnsignal system in use on the early vehicles were comparable in function to those on US civilian vehicles at the time.

The earliest of the three-lever light switches have a raised, triangular shaped face, and as ACE points out, did not have a socket on the back, but rathe two integral wiring harnesses with connections on the end of the harnesses.

Regards,
David

 

[gimpyrobb]

RE: Re: RE: 3 Lever History

Whats the knob on the speed-o for/do?

 

[Jones]

RE: Re: RE: 3 Lever History

I've got a variation in that the connector comes out the side but all of them tap into the brake light circuit for turn signal application.