Ford: check engine light, ford crown vic, battery cable

Question
check engine light only comes on when I am highway driving its a 1993 ford crown vic

Answer
have the codes scanned and reset, advance auto or NAPA can do this for you. after is has been scanned and reset (write down the codes that it had) drive it see if it comes on again, i may be just a old code stored in memory. don't try the pull the battery cable method, it doesn't work with fords, they have active rewritable memory, kinda like a cassette tape or CD-RW, they might not have power but the information is still there.