1998 Mustang. Has my car smogged today, failed for two reasons, no check engine light and no speed sensor. The speed sensor I knew already, the speedometer has been dead, but never found out why. The check engine light not coming on was a surprise. Related?
I took out my dash and checked the bulbs, I actually switched the chck engine bulb with the seatbelt bulb, one I knew was good. Still didn't come one, so not a bulb issue. Oddly when I had everything hooked back up and started my car, my theft light kept flashing. I accidentally stumbled upon a backlight for my instrument panel, which was pretty cool to see, not sure how I got it to turn on but it will defiantly make night driving easier.
So, what causes the check engine light not to come on? And is it related to the dead speed sensor? Is there maybe some electrical issue in the instrument panel causing these quirky problems?
Please be detailed, I'd like to check these things out myself if possible.