ray_vr6 1 Posted February 14, 2012 I'm installing an oil pressure gauge and a Volt meter to my 16v. I understand the best feed to the volt meter is directly from the battery. I read somewhere that a "switched relay" to an ignition feed is then required but what kind of relay am I looking for? TIA Quote Share this post Link to post Share on other sites
Abdul 0 Posted February 15, 2012 If you've got an aftermarket stereo use the remote cable on that. When you turn on your headunit your voltage display will turn on. That's what I did. Quote Share this post Link to post Share on other sites
fendervg 32 Posted February 15, 2012 The positive feed from the glovebox light is a good one to use. Quote Share this post Link to post Share on other sites
davidwort 0 Posted February 15, 2012 Do you want an accurate reading from the battery or just an indication of voltage? Most of the circuits fed off the ignition switch show a big voltage drop, all that old wiring and switch contacts. Best thing to do is fit a new fused relay to the battery and then use something in the dash as the switching feed to the relay, something switched on with ignition like the heater blower circuit or glovebox light. Just use a regular 12v 4 pin relay, from maplins, halfords etc... it will need an earth, +12v from battery, with an inline fuse, a feed from an ignition switched circuit and finally the feed out to your gauge. Quote Share this post Link to post Share on other sites
ray_vr6 1 Posted February 15, 2012 Thanks Guys - I did want to try and get an accurate reading and as mentioned above I have read somewhere that the old wiring etc does lead to voltage drop - also I have already piggy backed off the glove box and ciggie lighter feeds for a lights on buzzer. So I will source a 4 pin relay and mount as suggested Thanks Again Quote Share this post Link to post Share on other sites