fuel pump relay

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codfish146

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only have 5v orange wire at relay 91 suburban any ideas
 

84-C20

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None of us are going to have any idea how to help you with basically no information.

What relay?
Where is it located?
What problem are you trying to solve?
What engine and transmission in the rig?
TBI or Carb?
Is it the 1991 Suburban?

Pictures of the relay would be a plus but not absolutely needed.

Since I see this is your first post welcome to the forum, we really like it if folks new to the forum share a few pics of their truck and talk about it a bit.
 

gmbellew

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I'm fighting a problem on the same circuit. potentially there's an issue in the orange line shorting to ground and losing strands on the MAP sensor bracket or valve covers. I'd look over that harness really well. the orange line has constant hot off the ECMB fuse.
 

84-C20

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I'm fighting a problem on the same circuit. potentially there's an issue in the orange line shorting to ground and losing strands on the MAP sensor bracket or valve covers. I'd look over that harness really well. the orange line has constant hot off the ECMB fuse.
I'm impressed that you knew all that from the color of the wire.
 

gmbellew

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I'm impressed that you knew all that from the color of the wire.
been studying that circuit for a bit....

orange comes out of ECMB in main harness from fuse panel. goes to the first big harness split on the passenger side, then splits into 4 runs. 1 back to oil pressure switch, 1 to fuel pump relay, and 2 to ECM for constant power.
 

codfish146

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fuel pump relay sorry new to forum 5.7 auto relay located left side tbi new pump not working
 

gmbellew

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there should be a wire hanging off the relay harness to test the fuel pump. apply a fused 12v jumper to it and check the pump.

the orange wire should have constant 12v. the key to ign should close the relay and send power down the tan/WHT wire to the pump.

my previous post describes the hot side of the circuit.
 

84-C20

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fuel pump relay sorry new to forum 5.7 auto relay located left side tbi new pump not working
Your fine, it was me that was wrong. I didn't think anyone would know what you were talking about by just the color of the one wire. I wish you the best of luck fixing the problem, Glen will for sure be a good guide for ya!
 

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