I'm installing an Omori electronic boost guage. I've got the BOV tapped and into the sending unit, got the sending unit mounted and wire into cabin, got the boost gauge mounted (steering column), but am stuck on the power wires. I want my gauge to dim, like the oe gauges. I am prepared to go behind the radio (ala oe boost gauge instructions- except they had a pug/play harness).

I've got five wires:

1. brown- instructions say don't use- easy enough
2. black- ground- will ground in approiate place
3. another black- says you don't need to use-easy enough

Here are the two I need help w/

4. red- 12 volt constant- don't know where to go
5. white- light source- I'm guessing this is what makes it dimmable?- again don't know where to go

I've got the appropriate vampire taps, need to know where to tap.

Thanks in advance.

Big Sky

get out the manual and put the constant power wire into the radio fuse. i connected the white wire for the light to the purple wire on the cruise control harness, i can't dim the gauge but other than that it works perfect. o yeah the red power wire, fold it arround the fuse and stick it back in and vola!

12V constant is a blue with green or yellow stripe. i think there's only one blue wire with a lighter color stripe behind the radio, it also goes up to the clock harness and there are only 4 wires up there so you could look there to double check the color. if you want, all of the wires you need are also under the clock, but taking that top piece out is pretty annoying.

if i remember correctly, light source is purple. dimming is a different wire, but i'm not sure if you want to use that. i've heard of people blowing up the relays from tapping stuff into the dimmer switch on other cars. but the gauge should have some sort of illumination change on it's own, so try the purple wire first.

datdudedennis, how come you tapped off the purple wire at the cruise control harness? or was it just closer to your mounting location?

oh yeah, you should probably post something like this in the car audio, video, and security forum. they pretty much handle most of the wiring stuff

Big Sky,
You can buy the Hitachi Clutch Coil Socket that plugs into the back of the radio wiring harness, leaving two wires, one for 12V constant, the other for the varying rheostate voltage wire. That's probably your easiest solution. The part number and more detailed install directions are on www.ravensblade-impreza.com, under boost guage install (with pics). I wrote it and took all the pics, email if you have any more questions.
Loren

lorenjacobi@hotmail.com

ps YOu don't need a ground, just 1 constant and 1 varying voltage. And it doesn't matter which side of the guage they go to, current will flow either way.

Well after souring numerous threads, I think I discovered something- that mechanical gauges use only two wires- and one would be able to use hitachi socket and get dimming, but w/ a electronic gauge three wires need to be used- one to a 12v ignition, one to a light source, one to ground.

What I ended doing is going to the clock to tap- red wire -> yellow /w stripe- (12 v ignition); white wire -> pink w/ stripe (illuminaion); black-> black (ground).

Big Sky

It's hard to get dimming on gauges with single wire illumination hookups. Subaru dimming circuts use a floating ground dimming system. I spent an hour last night looking for a dimming wire before I finally realized the dimming circut is referenced from 12v+ instead of from ground.

On my autometer gauges that have the little bulb socket, I have both a separate ground and +12v wire, and so I connect one to +12v and one to the dimming wire, and I get dimming.

People with single wire-gauges probably can't do that, unless the gauge is designed with floating ground dimming in mind.
-Brad

I think your right. Well that's one disadvatage of an electronic boost gauge- at least the Omori anyways.