live feed for boost gauge

[Andy annear]

Hi guys,
firstly, sorry for another nooby boost gauge thread, searched around and have read numerous threads, however, not found much info for somebody like myself who isnt the most clued up on 306's yet!

ive read best placed to route the vacuum pipe and where the gauges can be mounted etc, but the live feed part confuses me

I'm looking to mount a gauge in drivers side vent, but the live feed and earthing parts im unsure where to go? obvs earth to chassis right? but the live goes to where? lights im presuming so it illuminates when the lights are turned on? if so where is the feed for headlights?

Sorry if this is basic but im a new 306 owner have some patience lol

Edit: what diameter t-piece do i need to give a good fit on a bosch compensator pipe?
Ps, any good gauges anyone recomends would be greatly appreciated,

Andy

[Jimbo]

I went on the wires for the dash dim switch. Then earthed behing bonnet pull lever

[Andy annear]

but how do I join the gauge wire onto a live feed? is it soldering job or similar?

Cheers

[Sambarker]

You can use solder, or crimp on connections, or connector block, or like most cretins do twist the wires together and put Sellotape round them (which I wouldn't advise)

I found the best feed for the gauge is if you take the panel off where all the fuses are there is usually a row of green relays. Every 306 I've had has had a spare socket without a relay. If you use a multimeter to test the outputs one of them will be an earth/ground and one of them if my memory serves me correctly will be a switched live with the key. If you want the boost gauge to be lit up all the time when the car is running (handy if you've got a smoked gauge) then you could use that as your feed.

Alternatively you can tap into the headlamp adjuster wiring which will give you both a switched live and also a live when the headlights are on.

Or even more alternatively, if you have an aftermarket head unit you will probably find that there is a feed for the illumination for the standard radio which won't be used any more which you could extend over and have that as your 12v feed which comes on with your headlights.

In addition to this you could also have a switch on a live cable to turn the gauge on as and when you like.

[WiNgNuTz]

I wired mine into the switched live on the head unit, but mines a smoked face, so needs to be lit up at all times.

[Andy annear]

Epic, cheers for the advice! now i know a few places i will decide where / how i want it to be fitted and start progress!

Thanks, Andy