Fuel pump wiring issue LS Swap

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jfkelley

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Guys need some guidance..I have an 1976 K10 4x4 with 5.3 /4L60e with stand alone harness ..I have power to everything except my fuel pump wire coming out of the harness ..I can get it running with the wire straight from the in tank fuel pump to the battery ..I ohmed the relays everything checked out ..Need to get it running right to get it to exhaust shop & Tuner ..Any suggestions? ..Thanks in advance
 

Bextreme04

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Is VATS turned off in the tune?
 

jfkelley

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Is VATS turned off in the tune?
Yes sir it has a Basic tune in ut ..It starts and runs but only with the fuel pump wire connected directly to the battery ..
 

jfkelley

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Is my old harness reworked by BC Performance out of Oklahoma
 

TotalyHucked

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Check all the connections on the back of the relay plugs, sometimes those don't get pushed in all the way
 

Camar068

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10 yrs Air Force
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Guys need some guidance..I have an 1976 K10 4x4 with 5.3 /4L60e with stand alone harness ..I have power to everything except my fuel pump wire coming out of the harness ..I can get it running with the wire straight from the in tank fuel pump to the battery ..I ohmed the relays everything checked out ..Need to get it running right to get it to exhaust shop & Tuner ..Any suggestions? ..Thanks in advance
look on the backside of your fuse block and make sure someone didn't solder the crimps on and filled the hole for any of the connections. I did that so when I pushed the relay in...it pushed the wire out the back because the slotted connector was full of solder.

lol was a DA moment for me lol.

[edit]pull your fuel relay and make sure the pins/wires aren't pushed out the back, and also not filled with solder.
 

jfkelley

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Guys on these two pics attached where it states #86 on the relay Red Fuel pump power wire can someone tell or show me where this wire goes to @ the fuse box ?
 

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hogdaddy

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It goes to any ignition "on" fuse under dash. Get test light and probe, Either piggy back a fuse or find an unused ignition socket and buy the right plug.
 

jfkelley

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Found an unused plug that said AC on it turned key on touched probe to it and said 12 volts put a spade on the 14 gauge wire and plugged it in ..Thanks!
 
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CalSgt

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It goes to any ignition "on" fuse under dash. Get test light and probe, Either piggy back a fuse or find an unused ignition socket and buy the right plug.

Found an in used plug that said AC on it turned key on touched probe to it and said 12 volts put a spade on the 14 gauge wire and plugged it in ..Thanks!

Whatever power source you choose make sure it is hot during “run” and “start” otherwise you’ll starve the injectors when cranking.

Did you ever notice that many electronic accessories in a vehicle stop working when the key is in the “start” position? There’s only a few items that remain on to direct all of the juice to the starter.
 

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