Where is the ecm on 91 Chevy s10 blazer?

The ECM (Engine Control Module) on a 1991 Chevy S10 Blazer is typically located under the hood, on the passenger side fender well. However, its exact position can vary slightly depending on the engine and specific trim level. It's often secured to the inner fender apron with bolts. You'll likely see a rectangular black box with numerous wires connected to it.

To be certain, it's best to:

1. Consult your owner's manual: This is the most reliable source.

2. Check online forums: Search for "1991 Chevy S10 Blazer ECM location" on forums dedicated to GM trucks. You might find photos to help you identify it.

3. Look for a large, rectangular black box with many wire connectors: While not foolproof, this is a good visual clue.

Remember to disconnect the negative battery cable before working near any electrical components to avoid accidental short circuits.