Dumb question about light switch

[Guigui]

Hi, I have this mostly new to me b275 and the wiring is kind of a mess. It is missing ths tag on the light switch also. I wonder what all the positions do on the switch. I looked the owner manual and searched a bit on Internet but did not find anything

 

[caterpillar guy]

Having only been around on 275 to load it and no more. IF the switch is like the rest of them. IT either has off dim bright and some are so they have bright and tail light. some even had a small red light mounted on top of the rear light When the switch is in one position or the other. Our H has O D B. I have heard of some having a connection to a thidr bruskh or something like that to set the generator to charge more when the lights are on. Again don't know anything about that not having seen one.

 

[JimB2]

Hi we never had a B275 but had a B414 which was the same tractor but with a the larger BD-154 vs BD-144 engine.
I looked in the B414 Operator's Manual Page 13:

Light Switch,
This is a four position light switch.
First position operates the side and tail lights, second position operates side, tail and dipped(Low) main beam,
third position gives side, tail and full(Hi) main beam, fourth position full(Hi) main beam only.
The Op's manual includes the original wiring diagrams for both Gas and Diesel B414s.

 

[BarnyardEngineering]

I would truly be surprised if it's not in the owner's manual, but IH tractor light switches generally have "off," one or two "road" positions and a "field" position. Of course this is a British tractor with a Lucas electrical system so all bets are off, LOL.

 

[Guigui]

I just went through the owner manual again, it shows how to adjust the valve lash but not how to operate the light switch. times have changed, I guess on new tractors it shows you how to turn the steering wheel and nothing on the valves...

That being said, I found a picture of the original labels for my tractor but not sure what S, D, M and P means. I Assume S stands for signals and P for Plough but not sure about the rest

 

[Guigui]

(quoted from post at 10:37:54 02/14/23) Hi we never had a B275 but had a B414 which was the same tractor but with a the larger BD-154 vs BD-144 engine.
I looked in the B414 Operator's Manual Page 13:

Light Switch,
This is a four position light switch.
First position operates the side and tail lights, second position operates side, tail and dipped(Low) main beam,
third position gives side, tail and full(Hi) main beam, fourth position full(Hi) main beam only.
The Op's manual includes the original wiring diagrams for both Gas and Diesel B414s.

So after re-reading your description, on the label, S for Side, D for Dipped, M for Main and P for Plough, it makes sense now