1995 Buick Roadmaster BaseFACTORY OEM SERVICE PROCEDURE

Hall Effect Switch (4.9L)

  1. Disconnect distributor 4-wire and 6-wire connectors. Apply battery voltage to Red wire of 3-wire distributor connector (distributor side). Connect ground to Black wire of 3-wire distributor connector (distributor side).
  2. Connect voltmeter positive lead to terminal "E" (Brown/White wire) of 5-wire distributor connector (distributor side). Connect voltmeter negative lead to terminal "D" (Black/Red wire) of 5-wire distributor connector (distributor side).
  3. Bump starter and note voltmeter reading. When distributor blade is in window of Hall Effect switch, voltmeter should read within .5 volt of battery voltage. When distributor blade is not in window of Hall Effect switch, voltmeter should read less than .5 volt. Bump starter several times to cause both conditions to occur.
  4. If Hall Effect switch is functioning properly and starter is cranked, voltmeter should show an averaged voltage of about 5-6 volts. If Hall Effect switch does not function as described, replace Hall Effect switch.
Factory Service Tools

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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.

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