Getting no electrical on Sniper set up

Just to set the scene: I’ve been working on the Bronco nightly this last couple weeks to finish up the install of the Sniper EFI. Keep in mind I’ve also added a new intake, EFI exhaust and upgraded to the 3G alternator during this project. I finally finished my last bit of wiring today... Go to set up the Sniper and absolutely nothing. As in nothing happens at all when I do anything with the key. No accessory power, no power on run, no switch clicks. It’s just nothing.

So now I’m on trouble shooting. The battery is full charge and I have everything connected to it on correct polarities. The only adjustments I’ve made to the original wiring system is the alternator install and tying into the ignition power line as a switch for the EFI power.

My first assumption was the EFI power up, but I believe I’d still have accessory power on that correct? The alternator on the other hand seems like a more likely culprit considering it directly affects the power supply.

Looking for any other suggestions. Otherwise, I’m going to revisit my alternator wiring.

Just a guess, but maybe you put the fuse links on the wrong side of the starter relay?

No, all the wiring us original on the starter relay. But if the power to coil is messed up in some way (I tapped into that as a switch for the EFI), will that affect everything else? Does that potentially trigger the starter relay?

The alternator shouldn't effect anything connected to the ignition switch.
If the battery and yellow cab power wire are both on the hot post of the starter relay the 3G is not going to change that.

You need to see that power is constant to the ignition switch, and that (key on) power is getting to the keyed side of the fuse panel.

I’m thinking I need to look at where I tapped into keyed power.

If you really just tapped in then there shouldn't be a problem.

But what do you mean about you "tapped into that as a switch for the EFI"?  If you are using the ignition power to pull in a relay then ok.  But if you are trying to run the EFI off that then you will have problems.

I'm with Jim, it sounds like the issue is with the power wiring at the starter relay or in that area.  Probably something done during the 3G swap.

No, it’s just triggering the switch of the ignition.

I’ll check both set ups.

Wait a sec... Can someone confirm - should the larger gauge yellow wire be connected to the starter solenoid and be going to the alternator rather than straight to the alternator?

Actually according to the instructions from painless - the yellow wire should be going to a constant source battery. I’m think the yellow wire it’s connected to isn’t constant source. If I move it to the solenoid, I think I’ll be in good shape.

Tested and failed. Last stop is the red/green wire. It mustn’t be key on... My only other option are red and yellow/green.

The large yellow wire (37) should be on the same stud of the starter relay as the positive battery cable. (Hot at all times)

Alternator output should be Orange/Black.

LtGrn/Red should be key on power. But if you don't have 37 Yellow hot at all times you won't see that, will you?
37 feeds the ignition switch and the always hot segment of the fuse panel.

If it is connected to alternator output (and not battery +) you will have no power until the engine is running.
This is going to be a problem if you need power to engage the starter relay......

Jim! That was it! Thank you!

Now on to the next issue... LOL

For your Sniper installation, did you have to cut a hole in the exhaust for the O2 sensor?

Nope. The y pipe came with an O2 bung built in.