A few months ago, I replaced the heater core in my 1993 Chevy S-10. That night, I was on my way to class when the instrument light went out. I suspected the tail lights had gone as well, so I pulled over and sure enough, the tail lights where out. The headlights, brake lights, and turn signals worked fine, but no running lights or instrument lights. I checked the "Tail lights" fuse, and it was blown. My first thought was that I may have pinched a wire under my dash during the heater core replacement, so I checked all of the wires that were visible and found nothing abnormal. So I replaced the fuse and started the truck. I let it sit in the driveway for 20 minutes, no blown fuse. So I drove it around town for 10 minutes, no blown fuse. It occured to me that when the fuse blew the first time, I was on the interstate, so I headed onto the interstate. After reaching 70 mph, sure enough, the fuse blew, exactly as it had done the first time. I'm baffled. What difference would speed make? If I keep it around town, no problem....I take it to highway speeds and the fuse blows! Anyone have any idea what could cause this?? Thank you in advance for your help.
Morris