It's good to know they work. Without a fault/failure I always wondered if they would work. I had a slight squeak from one of the belts that started last Friday. It would happen at idle, and when applying the gas, after she warmed up it would go away. I retightened them and sprayed belt dressing, that worked for about 15 minutes. I left for work this morning at 4:30a, within 5 minutes the battery warning light came on and the voltage gauge dropped to 9 and the squeaking went away. Has to be the alternator. She still took me to and from work 40 miles, and safely back in the garage.

 

I don't wanna sound rude but....whats this thread about lol? Are you asking about your belt problem or how to test all the lights??

Basically you'd look at all the sensors and see how they function, depending on that test them. basically you should just need a multimeter to check voltage going to them and resistance in them ( i think?)

As for your belt...maybe need a new belt. This is pretty typical of V belts when an edge wears away and some water or dressing temporarily fills it. Also make sure its tight enough obviously.

tightening the belts on these cars is unnecessarily tedious in my opinion and if you think you are done, chance are you aren't.