Block heater location

My stupid question of the day...it is warm enough that i will never need use it, but out od curiousity, where is the block heater plug in an 86 300SDL? I believe it was a standard feature, not an option, but looking around the engine compartment i can't see it. I was told it would look like just a regular electrical outlet plug. Is it under a cover or tucked away somewhere? TIA, Shannon 86 300sdl 289,000m