O2 sensors fuse in engine compartment box?

1998 DODGE DAKOTA
150,000 MILES • 3.9L • V6 • 2WD • AUTOMATIC
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WILL HURLEY
I am having a crank with no start problem. I've checked everything I can possibly think of fuel at rail is 49PSI, spark is present when cranking, etc. So, I went to the ASD and Fuel pump relays to check them, and relays are in working order, but I also checked fuses in that box and every fuse has power on both sides except the O2 sensors. I pulled the box and inspected wires on the underside, and all looked fine. Is this fuse fed as constant power, or where does it get power from?
Aug 30, 2023 at 2:16 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,193 POSTS
  • ASE Certified Mechanic
Hi,

Fuse 3 (30 amp) in the power distribution box sends power to the ASD relay. From the relay, power goes to fuse A which is responsible for powering the oxygen sensors.

Take a look at the schematic below and let me know if this helps.

Take care,

joe

See pics below.
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Aug 30, 2023 at 9:05 PM
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