FIRST and MOST IMPORTANT is to verify that you have at least 10 psi of oil pressure with the engine running. Assuming you have gauges, you can verify this by the oil pressure gauge. Once you are sure that the oil pressure is above 10 psi with the engine running, check the choke MIL circuit as follows. (your CHOKE light is always ON so you can skip the first 2 steps):
TROUBLESHOOTING
On some models, the low oil pressure indicator light also serves as the electric choke defect indicator.
(SKIP) If Oil or ENG. (or CHOKE) indicator light does not light, check to ensure electric choke is not disconnected at carburetor.
(SKIP) Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit.
If indicator light stays on with engine running possible causes are:
Oil pressure is low, switch to indicator light wiring has an open circuit, oil pressure switch wire connector has disconnected or on some models, gauge or radio fuse has blown.
The oil pressure warning light should go on when the ignition switch is turned on and the engine is not running. (SKIP) If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on with the ignition switch on, replace the bulb.
If the warning light remains lit when it normally should be out,
Replace - or test - the engine unit (pressure switch) before proceeding further to determine the cause for a low pressure indication.
The warning light will sometimes light up or flicker when the engine is idling, even though the oil pressure is adequate. However, the light should go out when the engine speed is increased.