Location of oil sending unit 1991 gmc truck?

The location of the oil sending unit on a 1991 GMC truck varies slightly depending on the engine. It's usually located on the oil pan itself, near the driver's side. However, it *could* also be on the oil filter adapter or even on the engine block near the oil filter depending on the specific engine.

To find it definitively, you'll need to:

1. Identify your engine: This information is usually found on a sticker in your engine bay or in your owner's manual. Knowing the exact engine (e.g., 4.3L V6, 5.7L V8, etc.) will help significantly.

2. Consult a repair manual: A repair manual specific to your year and model GMC truck (and engine) will have diagrams showing the exact location of the oil sending unit. You can often find these online (like Haynes or Chilton manuals).

3. Look for a wire connector near the oil pan: The oil sending unit has a single wire connector going to it. Look near the oil pan and oil filter for a sensor with a single wire connected.

Caution: Be careful when working around the engine. Make sure the engine is cool and the ignition is off. Oil can be hot and cause burns.

Without knowing the specific engine, that's the best guidance I can provide. Using the steps above should help you pinpoint the exact location.