New South Boost Gauge Wiring Question

[HaydenTheEMT]

Whats up fellas? so I recently put in my New South Performance vent pod 45mm boost gauge in the Avant. The instructions said to tap into the BLUE/GRAY wire in the back of the headlight switch. The gauge initially worked for the first couple days. It idled about -20 as it should, but would spike about 25psi and hold like 22psi: obviously NOT what my 1.8t with exhaust is spooling at. And my gauge's lighting would only come on with the Parking Light switch engaged, sadly, so thinking I tapped the wrong wire. That was before the gauge quit reading boost as a whole. Now as I am off to troubleshoot, if someone could answer the question of which wire in the headlight harness is the power that will turn on my gauge lighting when my headlights are flipped on thatd be fabulous, because apparently the instructions arent right with the BLUE/GRAY wire. Also, boost leaks or vacuum leaks are indicated by low boost readings, right?...so how come mine was spiking and holding so high? Ive heard of "calibrating" the gauge, but couldnt find anything further on the matter. You guys are wonderful. Thank you for swooping to the rescue.

[old guy]

It sounds like you tapped the correct wire. Here’s the one I tapped for my Podi mechanical boost gauge. The gauge comes on and adjusts with the display lights. Worked fine for the past seven or so years. I did have to install a resistor to lower the intensity of the gauge light so it was at approximately the same level as the display background lighting. Is you gauge mechanical or electronic?

[HaydenTheEMT]

Ahh the 17 slot. Gotcha. Mine was on the 9 on the back side. My colorblind ass. Thank you. But still looking for answers on my gauge peaking at 25 or so.

[HaydenTheEMT]

Sorry for the double, it's an electronic gauge with a sender

[old guy]

Are you running totally stock tuning?

[HaydenTheEMT]

Totally stock tune. The only thing changed is Vagcomed to Rest of World. Laughing face. The gauge acts like it is running correct. Not acting erratic or anything. Just reads a rather high number

[amgraham]

I have the same gauge. Was completely stock when I first installed and it peaked at 7-9 PSI. Did Motoza 1+ and now it peaks at 22-24 PSI. Are you sure someone didn't throw a tune in there at some point? If so I would contact New South as your gauge or sender may be bad.

[customa4]

Another possibility is a cracked line between the wastegate and the N75. Have you scanned for codes? If you're boosting that high over the stock limit I'd imagine you would get an overboost code and go into limp mode.

[HaydenTheEMT]

The only codes it's throwing is 16395, 17526 and 17522 of the lower O2 sensor. I havnt put in the spacer I got with it yet. Wanted to see if it would throw a code or not. The 16395 is Camshaft A(intake) Retard Setpoint Not Reached then P0011 - 002 Lower Limit Exceeded - Intermittent.
I havnt put much thought into the camshaft code, yet. Thinking I will take it to a euro shop and ask about a tune. Maybe previous owner put a tune on it. I would be VERY surprised what GIAC/APR/WHATEVER tune would bump it up THAT high with a stock cat in the car still. My buddies B7 2.0t apr stage 2+ was like peak 18, maybe. I doubt it, but I am going to take it soon. So here's another question. I originally tapped the the 9 wire slot instead of the BLUE/GRAY 17 slot and the gauge lit up with the parking lights engaged. Now I tapped the correct wire and the gauge doesn't illuminate at all, but when I turn my headlights on, I turn them off and they'll flicker a bit and then stay on, fogs and all. Granted the city light mod is done and my car is set to Rest of World, I don't know what would make All of the lights stay on until I turn he car off. The lights on the headlight switch go back to normal but the green Headlight light on the dash display stays on. Very weird. I think I will ask New South for another sender if my tune is stock.

[customa4]

An easy way to figure out if there's a tune is to do a data log with VCDS. If the car is requesting a significant amount of boost more than stock, there's a tune. If the car is not requesting that increase in boost then you either have a mechanical problem or your boost gauge is not functioning properly.

[HaydenTheEMT]

I would data log but my VCDS and Amazon cable only works with the unregistered version that only does Scans for codes, there is a tiny bit of modification but the vast majority of the features are locked. I'm at work at the moment or I'd check, Know if you can data log with the free version of VCDS?

[customa4]

I would data log but my VCDS and Amazon cable only works with the unregistered version that only does Scans for codes, there is a tiny bit of modification but the vast majority of the features are locked. I'm at work at the moment or I'd check, Know if you can data log with the free version of VCDS?

Not too sure. Someone else may be able to chime in with that information. I had a knock off cable many years ago but have since purchased the Ross-Tech cable. I can't remember if I was able to data log or not on my old cable.

[amgraham]

I would be VERY surprised what GIAC/APR/WHATEVER tune would bump it up THAT high with a stock cat in the car still.

I don't really see how a stock cat would be a limiting factor for boost, or really have anything to do with it at all (unless it's clogged). Like I said mine is pushing 22-24 PSI and I'm on the stock cat. Only mod I did was Bosch 550cc injectors and the Motoza 1+ tune.

[old guy]

My GIAC big injector file boosted 18 to 22 psi, temperature dependant. OEM cat.

[HaydenTheEMT]

Gotcha. thank you all for the help