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06-02-2020, 07:33 PM
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#1 |
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Registered User
Join Date: Mar 2020
Location: The Woodlands,Tx
Posts: 588
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ocm fuel pump wire
I am wiring my fuel in tank fuel pump thru a relay . Is the wire from the engine harness a ground or a power wire? need to know what side of the relay to hooks up to. I am assuming it is a power wire
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06-02-2020, 08:39 PM
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#2 |
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Registered User
Join Date: Jun 2015
Location: Carlos MN
Posts: 2,132
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Re: ocm fuel pump wire
On the after market LS harnesses I've used they supplied a 12 volt wire to the fuel pump. The LS ecm supplies the ground to the fuel pump relay I believe.
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06-05-2020, 04:58 AM
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#3 |
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Registered User
Join Date: Dec 2009
Location: Independence Mo
Posts: 4,119
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Re: ocm fuel pump wire
The PCM supplies 12v to the fuel pump relay to turn it on.
__________________
My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html |
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06-05-2020, 04:25 PM
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#4 |
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Registered User
Join Date: Jun 2015
Location: Carlos MN
Posts: 2,132
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Re: ocm fuel pump wire
I think the older LS computers like before 2006 supplied the ground to the relay. After 2006 when they went to the 58 tooth crank the computer supplies the 12 volt.
I may be wrong. I'd ask the question over on LS1tech.com. Those guys over there are pretty good. |
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06-05-2020, 08:51 PM
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#5 |
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Senior Member
 Join Date: Jul 2009
Location: Athens, AL
Posts: 499
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Re: ocm fuel pump wire
ls1nova71 is correct. The PCM provides 12v to the fuel pump relay. That is true for both the 24x and 58x systems.
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06-05-2020, 10:43 PM
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#6 |
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chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 2,008
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Re: ocm fuel pump wire
are you asking about on the factory harness? I have a '13 4.8 LS with all the factory "x" connectors (underhood fuse box). the fuel pump conn. wire is grey and same gauge as the pink wire from my '86 truck. I think these 2 wires will splice together & then go back to the pump? ... I think?? LOL!! If you have a aftermarket harness I think the directions will tell you how to connect the wire.... hope this helps....
....good luck!! |
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06-07-2020, 11:26 PM
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#7 | |
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Registered User
Join Date: Dec 2002
Location: Cactus Patch So. Az
Posts: 4,749
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Re: ocm fuel pump wire
Quote:
So when the key is turned on (switched) the fuel pump becomes (relayed) hot with 30 and 87 to the pump So I am to believe that the ECM supplies the 12vdc with the key on or does it just get a switched 12vdc with the key on
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