Probably not worth creating a thread over, but i've searched and can't find the exact information i need.

When I bought my TII the lights for the speedometer and such werent working, so a friend of mine messed aroudn under the steering wheel somewhere by the fuses and somehow fixed the light problem, but he managed to disconnect the red wire that comes from my boost guage... to wherever. Question is, where do i put the red wire, which i assume is used to power the meter? Everything else with the gauge installation is fine, hose from the boost sensor and such are fine.

 

yea thats the wire that goes to the light bulb...

just hook it either to switched 12v or find the wire that only gets power with the lights are on. either way.

 

My problem as i failed to mention really, is that my boost gauge doesn't function at all anymore. The dash lights work fine now... but i have no idea where to put this disconnected red wire which i assume is to blame for my non-functional gauge. I took a look under the dash and saw ... plenty of wires and i have no idea really about what to do with this wire.. you mention hooking it up to a switched 12v... where exactly is this?

Pardon my ignorance, i've never done any simple or otherwise electrical work before.

 

Head to your local auto store, or radioshack, whichever is closer.

Get yourself a test light, and some wire splicers.

Turn your lights on then start poking the wires with the test light, if the light turns on then u found a wire with power. Then turn off the lights and continue to test hte same wire, if it stays on this is a hot wire, don't use it. If it goes off when the lights go off, turn the lights on again once more just to make absolutly sure.

If the light on your test light comes back on, then you found a wire that only gets power with the lights on. Take a wire splicer, and splice the red wire with that wire.
This is how I installed my tachometer on my 85.

 

is this a mechanical gauge? i assume not if it dosent work at all without power. if its electronic then yea get or make a test light and go at it. if its mechanical and it doent work then he pulled out more than just the red wire.

 

Did you spend more than 60 bucks for your boost gauge? If you didn't it is mechanical.

What year is your car? This is the S5 diagram....

The wire you want to tap is highlighted

 

It came with the car when I bought it two years ago. All it has running to it are two (I think) red wires and the hose from the boost sensor. Yes, its an s5. Thanks for the diagram, I'll work towards understanding it.

 

It is easy to understand...I can help you....

Look at connector E-11 with the no airbag. The wire at the bottom right of the connector is the wire you want to splice into . This wire is the power wire that actually dims all the lighting in the car. It varries the voltage.

The picture of the E-11 connector is the connector that plugs into the cluster switch. Also, you are looking at the connector from the back side (wire side).

James

 

do you have a vacuum hose heading out of your boost gauge going to the engine? does your boost gauge light up when you turn on the dash lights at night?

 

You said there is a hose coming from your boost sensor which would mean it is a mechanical boost gauge. There is something wrong with this hose, and that is why it doesnt work at all. maybe it is disconnected or it has been cut somewhere between the gauge and the sensor. As for the light, follow the directions everyone else has given you for those wires. Personally I did the guess and check method like tyrael6666 said. But like I said, if the whole gauge doesnt work check out that hose.

 

if your gauge isn't working at all it's either broken or your hose is cut somewhere. it should read the boost with no power

 

sorry Helpy Mchelperson but this thread is MONTHS old. I think he figured it out by now.