ECON light -- 87 turbo

[judgea]

Recently I had the timing belt changed on my 87 turbo, & had all v-belts, plugs, etc., changed. As you know, the job was labor intensive; many engine parts temp. removed. Anyway, since then, my little blue "ECON" light never comes on. (I guesss we all know what the light is for & when it should illuminate.) I doubt that it simultaneously went bad; everything runs perfect. I believe the mechanic must have unwittingly unplugged something in the engine compartment. Before I go back to mechanic for an open-ended search, does anyone know where this "economy" feature "plugs" or connects to the engine area?