Positive Diodes

1966 GMC PB25 Series 4.8L EngSECTION Positive Diodes

Disconnect battery ground cable at battery. Connect ohmmeter between "R" terminal and "BAT" terminal and note reading. Reverse connections and note reading. Meter should read high in one direction and low in other. A high or low reading in both directions indicates defective diode.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.