legacycentral bbs

I need to wire the light for my boost gauge, and I was curious as to where.

I've got the instrument cluster out (I've got a burnt out bulb that needs replacing), and I was looking behind it.

There is a GND screw (I can only imagine that this is the grounding screw), and there is another screw attached to one of the dim-controled illumination bulbs.

So I was curious, could I just loop the wire from the boost gauge and "sandwich" the wire and the screws?

Would that work?

Where else can I wire for power and ground? I want the gauge to dim with the rest of the interior lights, so that's a key important feature.

Any help would be great!

BTW: It's an Autometer Phantom gauge, mounted in a universal cup in the center of the tachometer. www.fastWRX.com (MachV Motorsports) was having a moving sale, so I drove to their store and picked it up. I was the first one there. I was in the back opening all of the Legacy boxes with one of the guys who worked there, hoping they had some BC gear (Boxes from SYMS, the Suby Production Rally Team. It seemed logical that they would have had some BC5/6 gear, but they didn't). I got the gauge and mounting cup for less than I could get the gauge alone from Summit. I was going to pick up a Momo Raceair full Leather shift knob too, but the Race knobs weren't on sale (50% off all Momo shift knobs, EXCEPT the Race knob. If it was on sale, it would have been $40).

So I was curious, could I just loop the wire from the boost gauge and "sandwich" the wire and the screws?

I don't understand what you mean here.

If your gauge is mounted in such a way that it can't ground through its body, run a grounding strap from some part of the car that is grounded to the GND screw; a short piece of black wire with ring terminals on each end will probably work well, since you can put the other end around another screw somewhere near the steering column.

For the positive side, do this:

http://www.graphics.cornell.edu/~v/dimmer/

I just wired the light on mine into the ashtray bulb. You can use any of the dash bulbs and it'll dim.

My wording was horrible, I meant make a loop of the exposed wire and screw the screw down on it. Like a ring terminal, but no terminal (I don't have any at my house right now, so I'd need to go buy some).

Here is what I am talking about in pictures...

Overview of rear of instrument cluster:



The GND screw (off to right on the above picture)



The other screw. Basically, I traced the ribon around and whichever illumination bulb it touched, I looked for a screw on that ribon.



I also noticed that only the two large bulbs have condoms, the other are just straight up bulbs, meaning that there is a green film on the cluster



Here's the gauge I have got



The light dealie, gotta have the red bulb condom!



The old ghettoness on the driveway...

Ohhh... you were talking about screws on the instrument cluster, not the gauge.

Umm, I don't think you should use those. I think you should tap off the illumination wires at one of the switches or at the radio or ashtray like 91White-T suggested. I think the cigarette lighter has a little illumination bulb behind it too.

But if you wanted to, you'd have to trace the traces from both sides of one of the illumination bulbs and see if they ever have a screw in them.

You can just loop wire around screws but that's kind of ghetto and not very resistant to vibration. A proper ring terminal is really the only way to go if you need to attach to a lug that way.

And if your gauge doesn't allow you to control the voltage at both sides of the bulb, do the thing on that page I linked to.

What do you mean allow me to control the voltage at both sides of the bulb? There is a picture of the bulb up there, you tell me what it means (it's the same gauge that Matt has, if you are familiar).

I'm horrible at all things electronic.

I want the bulb to dim, but I don't want to go to all the work of building that harness I don't think.

I've got no problem getting rid of the ashtray light. That thing serves absolutely no purpose but to spread a soft green glow over the abyss of the ashtray, and you can't even see the light when the tray is open.

Maybe I'll just tap into the ashtray light and see if the light is bright enough to piss me off, if it is, then I'll build up this dealie you described.

Yes, that gauge does looks oddly familiar. You'll love it, it's a good gauge.

I tapped my cigarette lighter light and it works off the dimmer. My advice is to quit trying to tap something within reach of the short wires that are on the gauge and get a two lengths of wire that are the same gauge and solder them to the gauge wires. Then it's no problem to tap another light source. You can reach the cigarette lighter light wires without removing any trim or anything either, which is nice.

Wierd, I tapped my Ashtray lighter too and I don't have dim....



I also attached my a/f to that wire and it only works when my lights are on... heheh

I didn't attach it to the ashtray light, I attached it to the cigarette lighter light and it works off the dimmer.

Well that's a good call Matt. I'll do that tomorrow. Did you just ground to the body?

I'll probably just crimp the wires together. Involves a lot less heat. Every time I have used a soldering iron, I seem to burn myself, lol.

Do you have the 30psi model?

BAC5.2 wrote:Well that's a good call Matt. I'll do that tomorrow. Did you just ground to the body?

I'll probably just crimp the wires together. Involves a lot less heat. Every time I have used a soldering iron, I seem to burn myself, lol.

You don't need to ground to the body. Connect both wires for your new gauge bulb to both wires on the cig lighter bulb.

Your autometer gauge has both bulb wires isolated from the chassis ground-- which is a good thing.

Spend a few bucks on an electrical wiring kit. They include a selection of various connectors and a crimp tool.

Quick - You probably attached one side to ground and the other to Illum(+).

The kit Steve's talking about is a pretty good investment. It'll run somewhere between 12 and 20 US dollars:

Yea, but I've got most of that stuff , it's just all over the place in my garage.

My dad is somewhat of a handy-man (Matt and Vikash, you might remember the bar in my living room, and the floor, and all the moulding. My dad made all of that [we built a "fake" floor to raise the floor up 6" from where it used to be].) I've got the crimper, tons of crimps and such, but I can just never find the stuff.

That's really cool about the bar...

Having the kit in the box like that helps you keep it all together. I'm very familiar with the "have lots of stuff but can never find it" situation.

Well, I got it all set up, and everything works

I ended up snipping the bulb end off of the ashtray light (since I never use it), and extend the wiring (using crimps and heat-shrink tubing) up to the light. It works, and even dim's, so it's perfect. Looks pretty cool, I can't wait to see it at night. Thanks for the help guys!

My VAC is still around -15 inHg, and that sucks . Idle is still around 1250 to 1500.

I don't understand how an engine can maintain an idle of 1250 to 1500 RPM without producing more than 15 inches of vacuum.

Your guess would be as good as mine. I'm plucking at strings here.

I had a buddy of mine (who works for the GM Performance Division) mention that some IAC valves need to have an initiation period, where you have to turn the key to "on" 3 times before you start the car. He said that's how it's done on Grand Am's, so I tried it, no luck.

Another odd SNAFU with the car, is when the green connectors are connected, it idles MUCH higher (around 2k).

And my Tach bounces around like a slut. Like it'll sweep really really fast to 4k then drop back down to 3k, then stumble around 3k (dropping and rising). Only did it a few times, and it only did it after I pulled the cluster to change the bulbs. Everything is plugged in correctly, so I don't know what the deal could be.

Way for me to bring a thread back from death... To get the dimmer function, should I tap into the all red wire,or the red wire with the green stripe. Thanks

You need both sides of the dimmer circuit.

ended up just tapping into deck power. It has a dimmer feature