1998 GMC Savana PCM and Fues box

1998 GMC SAVANA
122,500 MILES • V8 • 2WD • AUTOMATIC
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JOSEPINZON
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  • 1 POST
I have a 5.7L GMC Unique Conversion GMC1500 SAVAN My power control module (PCM) was recently replaced due to corrosion and continues to corrode after one month of installation. The PCM is on the other side of the engine compartment away from the battery. The brake fluid reservoir is directly above the PCM but is completely dry. Yesterday I pull my fuel relay because I wanted to test my fuel pump amperage and with no leads connected and no fuel relay my vehicle was able to run I thought it was weird so I allowed it to idle for about 5 min and I accelerated the vehicle and it continued to run. It obviously there is something wrong but this is above my experience level. Can you provide me some info of what it might be?
Sep 2, 2010 at 2:04 AM
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JDL
  • ✓ASE Certified Mechanic
  • 16,098 POSTS
  • ASE Certified Mechanic
My info showed an oil pressure switch in your fuel pump circuit wired in parallel with the relay. Once you have cranked it enough to bring up oil pressure, with about 4psi, that switch will close, the pump will run even with the relay unplugged.
Sep 2, 2010 at 3:25 PM
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