I have a 1988 Volvo 740 turbo wagon. The car failed smog last week because the check engine light will not turn on. I checked the bulb on the instrument cluster, and made sure all the fuses are working, but I'm not really sure what else to check. All the other warning lights work. Could it be a relay failure? Just looking for some direction in the hopes that I don't have to pay a professional.

 

Light off? You should be golden! Why is that a problem? Course in my state an old (89) car like miine (with CE light on all the time) still passes inspection. D

 

When you said you checked the bulb, how? I don't mean to be trite but,did you replace the bulb or visually inspect, or move the bulb to verify?