What would cause the ecm b fuse to continuously blow?

1991 GMC SIERRA
202,000 MILES
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TRAVISB88
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Already checked the fuel pump, fuel selector valve, throttle position sensor, and the harnesses pertaining to these things for shorts and found nothing.
Aug 27, 2011 at 4:13 AM
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RASMATAZ
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You have short circuit direct to ground from the component/wiring that the ECM B fuse powers
Aug 29, 2011 at 12:07 AM
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CARADIODOC
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A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.
Aug 29, 2011 at 1:32 AM
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RASMATAZ
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Doc -Old school technique-Very good, Have a nice Sunday
Aug 29, 2011 at 1:35 AM
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