Boost gauge dimmer wiring problem

[sroby]

I am tying to wire my boost gauge. Its a basic mechanical by new south redline edition. 3 wires. black for ground/ red for 12v ignition on/ yellow wire for dimmer. seems strait forward. sourced the 12v to the red with blue stripe. under dash from main wire loom. Rally sport website shows the similar write up. However they use the violet or purple wire on frs harness for 12v red on gauge. Black for ground. I get it. However Yellow for dimming I cannot source where I need to connect Yellow for the gauge to dim with the dimmer frs light control. It seems no matter where I attach it the damn gauge wont dim. FRUSTRATED to say the least.
I was reading through countless pages last night. I'm guessing this is controlled by pcm. I know I am not the only one to ever wire up a mechanical boost gauge no data logging no electric just plain ole style gauge I am pulling vacuum from the back of the sprintex, up to the gauge on my blockhead pod. I have read that it might be possible to tab the yellow dim wire from gauge to light dim wire off of radio harness. Can anybody who has performed this please give me some insight on where to tap the yellow dim wire from gauge to frs so boost gauge light will dim with instrument gauges. Thx for input. Steve

[Irace86.2.0]

Originally Posted by sroby

I am tying to wire my boost gauge. Its a basic mechanical by new south redline edition. 3 wires. black for ground/ red for 12v ignition on/ yellow wire for dimmer. seems strait forward. sourced the 12v to the red with blue stripe. under dash from main wire loom. Rally sport website shows the similar write up. However they use the violet or purple wire on frs harness for 12v red on gauge. Black for ground. I get it. However Yellow for dimming I cannot source where I need to connect Yellow for the gauge to dim with the dimmer frs light control. It seems no matter where I attach it the damn gauge wont dim. FRUSTRATED to say the least.
I was reading through countless pages last night. I'm guessing this is controlled by pcm. I know I am not the only one to ever wire up a mechanical boost gauge no data logging no electric just plain ole style gauge I am pulling vacuum from the back of the sprintex, up to the gauge on my blockhead pod. I have read that it might be possible to tab the yellow dim wire from gauge to light dim wire off of radio harness. Can anybody who has performed this please give me some insight on where to tap the yellow dim wire from gauge to frs so boost gauge light will dim with instrument gauges. Thx for input. Steve

Do you have a wiring multi gauge to check? Im guessing not. There are plenty if you can check. The dimmer is obvious because it is the dimmer. Are you trying to see if the gauge dims when you turn on your headlights or are you thinking the dimmer knob will adjust the brightness? If you are thinking the latter then you are assuming wrong, most likely.

[sroby]

Irace86. yesir in answer to your question I am probably wrong that's what I am tying to resolve. When I originally had it hooked up per that past post. I was trying to see while sitting in the car, car is off. crank it up lights are in the off position no illumination from boost gauge. Turn on light switch with key in on position you will have illumination from factory gauges and boost gauge. I want to be able to if needed turn down the brightness via the factory dimmer same as if you dimming the factory gauges. Night time falls its a little to bright reach over scroll it down a bit lights get dimmer including boost gauge. That's what I am trying to accomplish here.

Please giving me more of your input on why I am assuming wrong. I know my car has the auto headlight switch. Am I missing something here that while its in auto mode They self dim? Was just assuming again that once hooked up sitting in my garage ? garage lights off car off its dark/ I reach over turn on car lights with key on not cranked/ dash light are on boost light is on then you want to dimmer down a little via the knob. That's what I am trying to achieve. What I am I missing here. Not do able? Give me what you are thinking plsr....thx Steve

[Cockatoo]

The gauge wont be able to take advantage of the dimmer switch...

The easiest way to get the feature to work would be to tap into the illumination wire for the head-unit.

[rb6freak]

http://www.ft86club.com/forums/showthread.php?t=28800

I just tapped into the dim signal (purple wire) on my stereo, gauge lights go dark when my stereo does (set to headlights on).

Originally Posted by rb6freak

Showing some snap shots of my install and a brightness demonstration.

For the dimming feature - I tapped into the stereo harness. Purple wire with silver stripes on bottom right of photo (pin 10 of 10). It worked first try.

[sroby]

I am just about ready to surrender to the boost gauge dimming issue. The mechanical gauge I have is a 3 wire unit. It doesn't look like without re-inventing the wheel I am going to be able to get this unit to dim as I would have liked as with the factory cluster. I don't know maybe its this unit as it is only a 3 wire unit. I know on the back of this gauge it has a red sticker that says this is a 12 volt red neg ground unit. So the 3 rd wire is yellow, for the dimmer switch.
I have had great input from folks that are running boost gauges. Most of them have the 4 wires. Acre, and other Electrical engineers here on the forum have given me great input an confidence. But I promise this reverse neg volt PWM controlling the factory dimmer switch is frustrating. I guess I need to ask, out there which is the boost gauge manufactured as strictly for boost display(no data logging oil pressure) that will work for our cars, as pretty much a plug and play install that will dim?
If none exist as plug and play which will work as dimming? I have tried just about all combos with this 3 wire set up to no avail. I will get it powered up it illuminates perfectly. Just bright as hell no way to reduce glare. My Son had an SRT 4 neon in 2005 till 2011. It had a standard factory autometer white faced gauge. I m thinking it was an analog regular old bulb inside. I remember him saying even factory dimming it was still to bright. They pulled the gauge, changed the bulb to a less voltage bulb and it worked fine. This is a sealed unit. I didn't want to attempt to try and open it to look inside. I am going to talk with Steve at new south performance on tues. to see if its an led light inside or analog. Unless anybody knows? I can try and resist it down, however It doesn't have a separate hot wire for light by itself. I put 12 v constant or ignition on, ground it and it lights up..yellow dim wire connected or not. I am at a loss..but still trying to figure it out. Sorry Ultra- I was hopping this new gauge would work. This gauge is for Subaru wrx 2011 new south Gauge gau 018 The previous one I tried was the model gau 012 for the Vw GTI. I will update on any changes. stand by for more input from the group. Thx again, sorry for the rambling on. Steve

[sroby]

Just updating my mechanical boost gauge dimming wire project. I went with New South Performance. Steve from New South helped me out with a lot of his time and I appreciate it. I used their gauge for the Wrx they have the dimming situation figured out. This gauge fits the block 8 single pod perfectly, the depth is spot on. I am going to finish up the install tomorrow weather permitting as the remains from the hurricane are expected through Atlanta. I will post pics.
With his help its pretty strait forward. 3 wires are with their gauges ( simple mechanical boost gauge/no data logging. Black wire to good chassis ground/ red wire to 12v ignition on source and take the yellow dim wire from gauge and hook to frs/brz black and white wire factory dimmer switch. With this set up gauge will light up with ignition switch on. Boost gauge will illuminate and dim as factory gauge cluster when you move the dimmer switch. You want full bright for daytime its there you want to dim it down move dimmer and it matches the gauges as factory. Thanks to Irace86/Cockatoo/rb6Freak. Your input helps me keep the old brain tickin.
The gauge I went with is New South Performance gauge for the wrx gau 018. Steve is fantastic and I cant thank him enough for taking time out of his busy day to find a solution. Customer service above and beyond. Best regards Steve