This way you can sit and listen to the radio without everything else draining.
													
																	Check engine light doesnt come on with key on. 
								
	
		
	
																	There is 2 key modes on the switch. 
																	Radio on mode only allows you to use the radio. 
																	I doubt any of the things mentioned have any affect on the check engine light. 
																	Do not check resistances. 
															
													
								
	
		
	
																	The light bulb for cel has a power feed with 12 volts runing to it with key on all the times. 
																	A loose fuel cap is one of the most common reasons why the check engine light turns on. 
																	Ok it looks like fuse 7 in the dash fuse box supplies power to the check engine warning light. 
																	The same power feed in the cluster powers up the seatbelt light abs and a couple others. 
															
													
								
	
		
	
																	It then goes to the electronic control module. 
																	It notably prevents gasoline fumes from leaving. 
																	This is called the self test mode for the computer. 
																	The cap is a crucial part of a car s fuel delivery system. 
															
													
								
	
		
	
																	Here is the deal run jumper wire at diagnostic connection but instead of first 2 slots go with 1 and 4 if check engine light comes on its the circuit board in module under dash its about 2 inches wide 4 inches long either lite green or gray or black plastic tube box with a door on one end will be tape up alongside wiring cut tape open lid and there is a small circuit board that handles lie and codes from computer. 
																	Since you said the other lights work then. 
																	If the check engine light doesn t come on in the run position it means the computer failed the self test mode and there s a problem with the computer. 
																	When turning the ignition switch to the run position the check engine light should come on.