The check engine light on my 1995 Mercedes SL500 came on?
I took it to Auto zone to have the codes checked neither of us could find the plug in under the dash near the steering column I thought there was 2 one under the dash and one under the hood that only the dealer had the equipment for .Where is the location and is it obd1 or 2 ?
1996 and newer Vehicles have the OBD-II connector under the steering wheel dash area. Your vehicle should be an OBD-I earlier generation that has the connector location unique to that make year model vehicle. You may be able to read the OBD-I codes out on a dash lamp that flashes the codes in morse code style. Your OBD-I connector is probably located under the hood. Maybe an http://www.Haynes.com repair manual for your make year model will detail it's location and use.