If a resistance measurement in a generator terminal box shows a high reading, what is this most likely to indicate?

• A. A loose connection or poor contact
• B. A perfect connection
• C. A short circuit
• D. A grounded fault

Answer: (A)

A high resistance reading at a generator terminal box usually means the connection isn’t making good metal-to-metal contact. When a lug or terminal is loose, the effective contact area is reduced and any oxide or corrosion on the surfaces adds resistance, so the measured value climbs. Under load this shows up as voltage drop, heat, and potential arcing, which is exactly the kind of symptom you want to catch early.

If the connection were solid, you’d expect a very low resistance reading. A short circuit creates a strong, low-resistance path, not a high one, and a grounded fault typically shows a low-resistance path to earth. So a high reading specifically points to a loose or dirty connection that needs attention—re-torque, clean the contact surfaces, and recheck the connection to restore a solid, low-resistance path.