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Mercury 500efi no fuel pressure. Help lol

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Mercury 500efi no fuel pressure. Help lol

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Old 04-08-2021 | 06:56 AM
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Default Mercury 500efi no fuel pressure. Help lol

I have a 500efi that’s fed by an Aeromotive pump. I’ve check the pump separate from the efi system and it functions as it should. However when I turn on my ignition the pump doesn’t kick on now. What could cause this? What should I check? Thank you for your help. I’m lost on this and I don’t want to damage the ECU by accidentally shorting something
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Old 04-08-2021 | 07:30 AM
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Could use a motor serial number

Start by checking fuses,there on top the motor
Use a voltmeter and see if the Main Power Relay (MPR) energizes when key turns ON
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Old 04-08-2021 | 07:52 AM
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Old 04-08-2021 | 11:47 AM
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Originally Posted by AllDodge
Could use a motor serial number

Start by checking fuses,there on top the motor
Use a voltmeter and see if the Main Power Relay (MPR) energizes when key turns ON
The block is not original to the efi system. It has newer aluminum heads and a 525 cam. It’s a bit of a Frankenstein
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Old 04-08-2021 | 04:53 PM
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OK, let us know what you find
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Old 04-13-2021 | 11:24 AM
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It won’t let me post pics since I’m new, but it was definitely the fuses. The corrosion had destroyed them and the female pins in the dongle. It’s running great now. Thanks for all the advice
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