Location of block heater cord on my 2003 chevy silverado

MIne was on the passenger side inside the wire loom next to the shock. You can get to it through the fender well. It just looked like a ball of tape and only the plug itself was exposed with the rest of it doubled back on itself inside the loom. It was actually long enough to stick out of the front of the truck.

Information on the use and location of the block heater termed "Engine Coolant Heater" is found on page 2-24 of the 2003 Owner's Manual:
"To Use the Engine Coolant Heater"....
1. blah.. blah .. blah
2. "Open the hood and unwrap the elcetrical cord. The cord is located on the driver's side of the engine compartment, near the power steering fluid reservoir. If you have a diesel engine, refer to diesel supplement for location.
3. blah..blah..blah

If you haven't found it yet, don't be surprised it's not there. By the spring of 2003, certain parts weren't installed on my Silverado, like the lock on the tire jack access hole on the rear bumper, even though it was included in a GM print out of the equipment included on my specific truck (I discovered that in time and even though GM claimed it was a $20 option, I insisted the dealer install it free - which they did). And somewhere along the line, GM dropped the underhood light that was included even on my 2000 base truck. Along with the 2nd accessory power outlet on the dashboard. GM was slowly stripping parts from 2000 on up. Excessive warranty costs may have been the reason. But that's another story.

Hope my answer helped.

Mark

Found my block heater cord for my 2003 Silverado nicely taped up on the driver side underneath by front axle.

Look under yhr hood for a balled up cord on passenger sde and look in behind grill