yeah, i plan on only running them as signals not running lights.

Does anyone know where these brown & purple wires are located?

 

ok, apparently the problem is the grips/signals aren't getting a good ground on the bars. the bars are brand new powdercoated black. could this be the reason they aren't grounding?

 

I would think the powder coating would affect the ground. Even normal paint can effect the ground. You may have to scape the coating away somewhere that will be covered with the grip to make a good ground. I have never seen a signal with no ground (Black) wire, but it has to get ground somehow.

The wiring sequence is this.
The middle (tab #2) wire on the 3 wire signal AMP connectors is the signal wire. It is either brown or violet depending on right or left AMPs. The left AMP connector (not the wire) is white (OEM anyhow) and the right AMP connector is black.
But it's the middle socket pin you want on each AMP connector.

Before you go scraping powder coat, try plugging up the pins into the AMPs and see if the signals work. If they don't work, try moving the AMPs around a bit while the signals are on. It it starts to work intermittently you could have a loose pin/socket connection on the AMP which can be cured by removing the socket pin (usually in the male plug) and pressing the tab in with a small screwdriver. If they still don't work then you either have a break in the wire OR you are going to have to scrape the powdercoat.
What you could do to make sure is pull the bulb and put a test lite (the kind that work of the bike power) to bulb socket terminal with the test lite ground clamp on the engine rocker covers. If it lites then you are not getting ground.

Opps forgot to add where they are at:
The Front AMPs are in the frame neck at front. Remove the plastic gusset plate under neck next to steering column. You may have to slide the tank back to get to it if you don't have a 2" tank lift.
Unscrew the tank console and disconect all the electrical connections. The push button unscrews.
Pop the tank fuel line (left side rear of tank) put a towel around it, it will spray for a second. Then disconnect the fuel gauge connector (left side front of tank). Leave the crossover tube connected (pain to drain the tank) and put a large soft towel around the rear frame area of tank mount AND under the front of tank. Remove tank bolts and carefully slide tank backwards.
Once you start pulling the various harness wraps down you will eventually see the two 3 wire AMPs branching off of the main handlebar wire harness before it goes into Deutsch connectors (the ones with more than 3 wires).
You may have to pop the rubber grommets on the frame neck sides to fish your one wire thru it and down the neck. But if you pull enough of the wires down out of the frame first you may be able to fish your wire thru without popping the gromments. You really have to man handle them to get them out so hope you don't have to.

The rear AMPs are in the tail light housing, (they are only two wires, ((edit revise) running lites are same filament in one filament bulb, The front bulb has 2 filaments and 2 circuits with one ground. The rear with 1 circuit just burns brighter for turn sigs on the one filament)) But anyhow I think you said it was the front you are doing.
This should get you going.

 

Thanks RWB, tested you're theory & it looks like for sure a grounding problem.

The left grip has a set screw, so it could get ground that way, but the throttle grip doesn't actually sit snug on the bar since it has to be able to rotate. So, i'm wondering how it is supposed to get a good ground.

I saw a guy in the dyna forum with the exact same grips a couple months back, but i can't find him now.

 

You might try starting a thread named,
Anyone got these grip turn signals ?

Also I was a little confused about when you said

' I tried touching the ONE exposed wire from the signals to all the wires in the plug while the rear signals were on. I got a very small spark from the middle wire (I think is the hot-brown wire on the right side plug) but it still didnt make the signal come on. '

What plug (or where) was this plug you were touching the one wire too ?
It sounds like the correct plug but not sure without knowing where it is.

 

It was the 3-wire turn signal plug coming out of the frame.

I have it all wired up correctly & the left side works, but the right/throttle signal can't get a good ground. I can't figure it out!
You would think the grip would have to be tight on the bar to get a good ground, but it can't be tight since it's the throttle

 

you'll have to upgrade to dot 4 signal fluid or they will never work right.just saying.