Fuel Pump Not Priming Key On

[92GreenGT]

Car is on the AEM EMS and has some stuff removed from the harness:

No emissions stuff
No O2 harness
No EEC test ports
Factory coil wiring has been removed
No MAF wiring
No A/C(wiring is still in place though)

Figured I'd get that out of the way, the car has GM LQ9 truck coils. Everything works correctly minus the fact the fuel pump will not come on when the key is turned on.

Inertia switch has been tripped and reset but had no effect on it
Fuel pump relay has been replaced

Fuel pump WILL work when using a jumper wire from the 12v always "hot" source over to the wire going back to the pump. What wire on the relay do I need to trace that is the "keyed on" power wire? Any help is appreciated.

Thanks!

 

[89CobraGT]

Did you check you're fuselinks?

 

[liljoe07]

Solid red wire should be the Key activated 12v source. But, the ECM is what controls the relay ground to turn the relay on or off.

Key on and the ground for the relay grounded( temporarily grounded), you should have 3 wires at the relay that are hot. Key on, and no relay ground you should have 2 wires that are hot(fuse link side and 12 ignition side).

Sounds like you have the Fuse link source. So its either the ground from the computer or the 12v switched thats missing.

 

[92GreenGT]

We put my AEM box in a buddies car(also AEM car) and done the Key on with it to be sure it was grounding like it should and his pump primed correctly.

So that takes car of the box as the issue.

The 12v switched is the wire I must be missing, which wire is it on the relay that does that?

 

[liljoe07]

Should be the solid red wire. But it comes from the ECM relay. So I'd start there first. Just make sure you have 3 wires that are hot at the ECM relay with the key on.