340B Gauges

My air filter light recently came on and I replaced both filters,the light stayed on.I called my tractor guy and he said just disconnect the sending unit.It was already disconnected?I removed the instrument panel and found 3 lights not connected to the cluster.I reinstalled the panel and the light went off.I have no idea if one of these other lights some how made its way close enough to make the panel illuminate?The alternator and oil light are the only ones that appear to be connected on my tractor.I would like to verify the water temp light/gauge is working.Does anyone have a wiring diagram for a 1987 340B?

its common to get in a tractor where someone has plugged in the lights to the wrong socket. SO...looking at the lights with two wires going to them,,, you have either an alternator light on or an oil light on. Unplug the sensor wire for the oil sending unit, behind the power steering pump,, and see if it goes out... if it does, plug that socket into the hole with the oil symbol on it.... reconnect the sensor for the air filter, and replace the bulbs if needed in the other two sockets to try to get them to work. If the alternator has been change to delco or other model, its common for the alternator light not to have be rewired past the regulator,,, assuming you have the earlier model ... Note... that when the tractor is NOT running and the key is on,,, there is a diode connecting the air filter light to the oil light, so that the air filter light will come on, any time the oil light is on. this is done so you can see and test the air filter restriction light before starting the engine. Also helps greatly get your attention if the oil pressure fails... two lights are better than one for a serious failure! let us know...

or you can get the wire colors and move the sockets to the correct holes using that method as well.