Resolved 2G Aftermarket Gauge Wiring to Dimmer?

[lewishamilton]

I've searched and read the few threads on wiring boost gauges to the dimmer switch but none really explains what I did wrong on my install.

I'm getting the gauges dimming opposite of the rest of the Instrument Panel (So Speedo bright = Gauges Dim and vice versa)

"Check the polarity. Before you solder anything, make sure the polarity is correct. Nothing will be damaged if it is not. If you have the polarity correct, as you rotate your dimmer switch the gauge light should get bright and dim along with the rest of the instrument lights. If you have it hooked backwards, as the factory instrument lights yet brighter, your gauge light will get darker. It will be the opposite of what the rest of the gauges are doing. If this happens, just switch the wires and you'll be set."
This is written on a step by step (I checked the site and the VFAQ

This seems like exactly what happened but I'm not sure how to fix it. Which wires should I switch? Right now I'm getting power at the stereo, ground next to the stereo under the console and the lighting wire at the dimmer. My gauges are getting power and working fine except for the dimming being the inverse of everything else. (It wouldn't be a problem except my gauges are extremely bright and distracting, I want a more OEM look)

 

[luv2rallye]

The dimmer is in the return to ground path, not the positive power path. So your gauge lights should have one side connected to switched +12v and the other side (side you normally would ground) going to the dimmer black-yellow wire (and not to ground).

 

[lewishamilton]

Okay I shouldn't run a dedicated ground at all? My gauge has three wires One for Switched 12v One for Lighting (depending on desired backlight color) and One for Ground.

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[1990TSIAWDTALON]

You hook dedicatd 12v to just that. 12v+ neg to ground. Last wire to any 12v source that comes on with your lites-gauge or parking lights. It auto dims when seeeing 12V On the 3rd line.

 

[luv2rallye]

Well looking at your diagram you may have a problem and it's going to depend on how things are connected inside the gauge. I'm assuming you have an electronic gauge (which has circuitry inside). If the black (pin 3) is used as a ground for the electronic circuitry (and not just the backlighting) which it probably is, you can't connect the black to the dimmer switch's black-yellow because it will provide a voltage drop there which will make your gauge's circuitry not function properly. In that case you'll have to give up the dimming function and just connect it the way they show (full intensity).
[Note: You also can't put the dimmer on the white (or brown) wire or you will experience inverse lighting (and lower intensity) as you have seen.]

 

[lewishamilton]

Okay I think that explains a lot. That above diagram is from Innovate's PDF Manual for the gauge.

• The Oil Pressure Gauge has been flickering when in use.
• I have a parasitic drain on my battery, also. Could the improper grounding be causing this?

I really wish I didn't have to run it full brightness but I'll get used to it I suppose unless I can figure something else out.

 

[brads]

I fixed it on my greddy electronic gauges years ago by isolating the wire that is the ground for the gauge lighting from the rest of the gauge ground, and tying that lighting ground to the dimmer.

I'm pretty sure I've seen someone make a module to make it work, but can't find it now. If you were electrically inclined, it should be as simple as a opamp to invert the dimmer output voltage and maybe a transistor to amplify this output to an acceptable level.

 

[lewishamilton]

Wow i'll do some reading but that seems like a significant job without the module you were talking about.

Will I damage my gauges if I leave them how they are?

 

[brads]

Probably not, but the post from luv2rallye tells you the right fix, for now. Attach the gauges to 12V, not dimmer