Overkill/too much time on my hands this weekend

[ko67]

I am putting in a small panel of aux gauges, temp, oil pressure and volts. It was a rainy weekend and I decided to build a neatly organized little wiring harness for the panel of gauges that makes it easy to remove when I decide to replace the whole instrument bezel.  I am more experienced working on watches than cars. My watchmaking training by the Swiss maniacs in Geneva preaches methodical perfection and planning. Here is a pic of what happens when a swiss trained watchmaker who is learning about cars from the internet builds a mini wiring harness for a gauge panel. It is assembled with soldered connectors, except for the suitcase taps that connect the power and ground wires into one. The harness terminates with sealed quick connect spade connectors to make it easy to remove. The lighting power leads are separate so that they can tap into dash lighting with clip on t-taps and spade connectors. Everything is shrink wrapped and the bundle is powerbraided. I intend to make the underhood wiring to the senders the same way with the spade connections all inside the firewall.

My question is this. Is it necessary (or adviseable) to attach the gauge ground wires to a source of engine ground under the hood near the sensors or can I ground them somewhere under the dash?

[gotstang]

Very nice! I have a friend that's almost as detail obsessed as you...do I spy expandable mesh sleeving and heatshrink?

I'd just ground it under the dash (to clean, scuffed metal, with a star washer, pointy side to the metal).

[garner67]

Very nice work.

I agree with gotstang... Other stock components are grounded to the dash, you might as well ground your panel somewhere on the dash.  If you want to add additional grounding "overkill", run a ground wire from the dash to the firewall, and another ground wire from the firewall to the engine.   

[Midlife]

You know what they say about watches that don't work: they are correct twice a day.

So...if things don't go well, the gauges at least will be accurate without the car running!



Nice job.

[ko67]

You know what they say about watches that don't work: they are correct twice a day.

One of my instructors in watchmaking school used this old phrase "a stopped watch is right twice a day" as an example calculation of beat error percentages. On a watch with a second hand, a stopped watch is correct to the second for 1 second every 12 hours, or 2 seconds in a 24 hour day. Since there are 60 seconds a minute, and 60 minutes an hour, there are 86,400 seconds in the 24 hour day. This means that the watch is correct 1/43,200th of the day, or .002314% of the day. It also means that such a watch is wrong 99.997% of the time. Cooincidentally, that is about how often I get something electrical right on this car.

[66gt350]

One of my instructors in watchmaking school used this old phrase "a stopped watch is right twice a day" as an example calculation of beat error percentages. On a watch with a second hand, a stopped watch is correct to the second for 1 second every 12 hours, or 2 seconds in a 24 hour day. Since there are 60 seconds a minute, and 60 minutes an hour, there are 86,400 seconds in the 24 hour day. This means that the watch is correct 1/43,200th of the day, or .002314% of the day. It also means that such a watch is wrong 99.997% of the time. Coincidentally, that is about how often I get something electrical right on this car.

Talk about way too much time on your hands!!! :lol

[blue65coupe]

Very sweet setup.

[apollard]

and another ground wire from the firewall to the engine.   

Shouldn't that one be there anyway? It was stock, although I think a lot of them got 'misplaced'.