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89 4.0 fuel pump problem

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Old Jun 9, 2015 | 09:55 PM
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Default 89 4.0 fuel pump problem

OK so I have an 89 4.0 Cherokee I put a new fuel pump in when hooked up to the stock wiring it DOSE NOT WORK but if I hook it up straight to the battery it works I've checked relays fuses there all good I have no idea why it won't work when hooked up correctly any one had this problem or know what it could be
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Old Jun 10, 2015 | 09:19 AM
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Have you checked for power at the plug?
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Old Jun 10, 2015 | 12:37 PM
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Originally Posted by J_White
OK so I have an 89 4.0 Cherokee I put a new fuel pump in when hooked up to the stock wiring it DOSE NOT WORK but if I hook it up straight to the battery it works I've checked relays fuses there all good I have no idea why it won't work when hooked up correctly any one had this problem or know what it could be
Check under the rear seat. The wire harness running to the fuel pump is right there behind the driver. You or someone may have tossed something there that broke the wire. Good luck.
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Old Jun 10, 2015 | 02:35 PM
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I've checked wires leading to the plug and when I crank the motor over I'm getting power checked with multi meter but no power when I just have the key to the on position
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Old Jun 10, 2015 | 05:11 PM
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Originally Posted by J_White
I've checked wires leading to the plug and when I crank the motor over I'm getting power checked with multi meter but no power when I just have the key to the on position
See if you have continuity across this with the key On. It's okay to bypass it.

Here
Attached Thumbnails 89 4.0 fuel pump problem-ballast-resistor.jpg  
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Old Jun 10, 2015 | 07:19 PM
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I have current to that I'd have to check again if I have going to both leads will it damage the fuel pump if I bypass it
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Old Jun 10, 2015 | 08:30 PM
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Originally Posted by J_White
I have current to that I'd have to check again if I have going to both leads will it damage the fuel pump if I bypass it
Will do no damage at all.
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Old Jun 10, 2015 | 10:04 PM
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Now correct me if I'm wrong but that turns the voltage from 12 to 9 voltage sorry if it's a dumb question wiring is not my cup of tea lol
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Old Jun 10, 2015 | 10:38 PM
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Originally Posted by J_White
Now correct me if I'm wrong but that turns the voltage from 12 to 9 voltage sorry if it's a dumb question wiring is not my cup of tea lol
Not a dumb question, and you are 100% correct.
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Old Jun 11, 2015 | 12:06 AM
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OK I'll try jumping it tomorrow and let you know what happens
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Old Jun 11, 2015 | 01:43 PM
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OK went to test the voltage to the wires for that resistor and now I'm not getting any voltage to it or to the fuel pump wiring in the car checked the relay and it's still good I'm lost lol
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Old Jun 11, 2015 | 01:55 PM
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Originally Posted by J_White
OK went to test the voltage to the wires for that resistor and now I'm not getting any voltage to it or to the fuel pump wiring in the car checked the relay and it's still good I'm lost lol
How did you check the relay?
Attached Thumbnails 89 4.0 fuel pump problem-renix-relay-center.jpg  
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Old Jun 11, 2015 | 03:12 PM
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I moved them around and have replaced the fuel pump relay
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Old Jun 11, 2015 | 03:13 PM
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Do you have power to the #30 terminal of the relay socket?
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Old Jun 11, 2015 | 06:48 PM
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Note from DJ
Pete I’m taking the liberty of adding some clarification words to your question.
With the key on” Do you have power to the #30 terminal of the relay socket?
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