1990k100E

Never saw me any switches like that. Actually never saw the inside of a similar truck. A 50's gas burner came in stock from Ft Wayne. Cab, chassis. air hookups. You put on fifth wheel, hitchhiker line holder, saddle tanks early/step tanks in say 54. Drilled a hole in the left end side of dash for a fused generic push/pull switch for trailer lights. Worked trailer lights with left hand, right hand for shifting/steering-other pastimes.

Age now is 87. As for Jimmy, only read about them finding him while doing the autopsy on Jeffry Dahmer.

 

Tachographs we had on some Bryan trucks had the speedometer cable and 2 wires. Needle showed speed, a motor turned the round treated paper disc to record as a graph.. Scraping needle scratched the white coating off the disc as speed varies, electric clock kept the time, (you positioned disc at your then time to start) Nice little disc record of you started at ??, ran speeds, stopped at ? time for how long, started again, ran speeds...New disc every 24 hours.
Mack had one on it, but we never used. Kept a set of 5 on 5 off log books with preplanned miles, state lines, etc.... Once logged Columbus MS vis SF to Seattle, back to Tumwater area while sitting in restaurant booth easting supper... Old times, sparse ICC inspections. Only one I ever was stopped at/examined
was just west of Tucson in 1957. Prior years were were exempt cargo, cattle, cotton , seed, grain, and anything you could get inside a trailer.

 

Fifth wheel and power divider

 

I wonder why someone duct the duct??

 

Controls probably stuck on heat in July and he needed some relief...

 

The one on the right says “normal operation” I’d guess like others, power divider. Though it might be a front brake 50% valve, used for bobtailing. Left ones missing the safety cover. Might be an air suspension dump switch. Might be an air ride “soft” setting switch for bobtailing.

 

Ahh sorry it was early...One on left I’m pretty sure is your power divider Right one either front axle brake cut off or fifth wheel slide
Try em and Ck
Also ck Paccar with VIN they might be able to provide original build sheet Might

 

I suspect one of them may have been for limiting the front axle brakes, which would be the "slippery" switch, and the other the power divider. I don't recall any trucks of that era having lockers. One should be the power divider for sure. I guess it depends on whether or not it had a sliding fifth wheel, in which case that would be the other option as many have mentioned.

Two speed rears would be the only other option that comes to mind.

Edit to add: The first truck that I drove was a 70 Pete, and it had a switch like that for the parking brake, but it was on the dash. A 90 model would not have had that.