on the rear bottom side of the oil pan, dont confuse it with the transmission on a automatic
Bottom of the radiator.
bottom driver side of radiator
I have a 2007 GMC Sierra 5.3L V8...and I just changed my oil and found the drain plug on the opposite side of where the Oil Filter is. The plug is a 13MM.
underneath there is a black, plastic safety shield. there should be a little 6" door with a screw, open this & you'll see the oil drain plug.
Bottom corner of the radiator, on the passenger side.
Next to the oil pan right above the oil drain plug
The 2004 GMC radiator drain is located on the bottom of the radiator. The radiator drain plug can be removed with a half inch ratchet.
Wear is drain plug on 1997 GMC 7.4
The horn relay on the 1993 GMC Sierra is located on the fuse box. The horn relay is a rectangular shaped plug next to two larger round plugs.
ON the rear bottom/side of the oil pan(under the truck), don't confuse it with the transmission drain if auto.
on the side of the oil pan you idiot
Bottom of the engine on the oil pan.