Mechanical oil pressure gauge install help (sorry if this has been discussed)
 

Hey y'all i have a few questions regarding installing mechanical gauges, again sorry if this topic has been discussed, but I could not find it doing a search.

I just picked up a Sunpro voltmeter gauge and mechanical oil pressure gauge, and was wondering whats the best source to tap the live/hot wires into for the 12v bulbs that come with the gauges.

Also where is the sending unit on the motor (3800 series II) that I need to run the tubing from the gauge to?

I appreciate any and all info/tips in installing these gauges as they are the first project on this sweet craigslist find.

When I install gauges I usually source the power for lighting from the headlight switch so they turn on/off with the rest of the instrument lighting.

The oil pressure switch is located near the oil filter. You will need to get an adapter so you can tap into where the original gauge is. Personally I don't like mechanical oil gauges. I don't like the idea of a tube full of hot oil being inside the passenger compartment. You may want to consider replacing the nylon tubing with copper tubing. Make sure you use a grommet where you pass the tubing through the firewall.

Awesome! Thanks for the info! What's the best way to get to the wires that control the headlights? I have absolutely zero knowledge/experience with wiring/electrical. I just ordered the copper line to replace the cheap rubber one that came with the gauge. Again thanks for the info/help!

I'm not familiar with the wiring of your particular vehicle (Z34). Best bet would be to have a look at a wiring diagram in a repair manual. Some libraries will let you photocopy the needed info. Another option is to purchase a repair manual. Examine the head light switch wiring, determine which wire powers the instrument lights and tap the + wire for your gauges into it. The ground wire can be attached anywhere to a metal surface under the dash.

I had a car with a mechanical gauge and the nylon leaked oil all over the carpet. It was an older car so I had space on the fuse box to pull power.

That's exactly why I don't like mechanical gauges in the passenger compartment. That's a good point, Lou. Sourcing power from the fuse panel is another option depending how the lighting is wired. That would be easier than tapping the light switch, so you may want to check that out on the wiring diagram also.

Awesome! Thanks guys!

Finally descent weather on a day off and I got the gauges installed, I took the fuse panel route instead of tapping into the headlight wires. Also ordered an electric oil pressure gauge to replace the mechanical one because I don't need any oil inside the car haha