New Boost Gauge in my Honda Civic. Part 1

New Boost Gauge in my Honda Civic. Part 1

My adventure installing a new gauge in my car!

A few months ago, I decided that adding some gauges would be a nice way to read some of the performance metrics of my car, to allow me to insure it’s running the way it should, especially when I am tuning the car to produce more horsepower and torque. The two metrics I want to measure are boost/turbo pressure, and oil pressure, to insure that my +6 PSI tune is actually producing the target boost pressure, and that my oil pressure is in the proper range, and the engine is running happily. I’m only going to talk about the boost gauge, as I don’t plan to install the oil pressure gauge until it gets warm again.

While it may seem easy to stick a gauge in a car, it actually turned out to be rather difficult, because of the things you will need. These things are:

  • A place to mount the gauge and the means for doing so
  • Proper power for the gauge
  • A place to attain a reading for the gauge

Mounting the Gauge

Gauges often get mounted in pods, and the pods are specially designed for your car to allow the addition of gauges, without it being aesthetically displeasing. In my car, this was a pod that replaces the driver side defrost vent. The A-pillar is the most common place to mount gauges, but the Honda Civic has a side airbag that deploys from the A-pilliar, and I decided that I’d rather not have my gauges doing their best impression of a fragmentation grenade’s shrapnel if the airbag goes off. The oil pressure gauge will go in a pod that sits on top of the steering column between the steering wheel and the existing gauge cluster. This is also a safe spot that is airbag free.

The gauge installed in it’s defrost vent pod. 

Powering the Gauge

This is the hardest part of the installation without a doubt, because cars have gotten more complex and harder to work on over the years, but luckily the Civic is not as bad as some others. The interior fuse panel in this vehicle is above the pedals, so it can be difficult to get to. The method I’ve always used to add circuits to a car is literally a device called an add-a-circuit, and it is shaped like a fuse on one end, and allows you to add a wire coming off of any of the fuses. In my case, I needed a constant power fuse, and a key-switches fuse to tap into. Luckily, I already had 2 add-a-circuits installed for a dash-cam, so I got to skip this step. I simply spliced my power wires onto the existing add-a-circuits. I only needed one more power, and it needed to be from a light-switching source, to tell the gauge to dim when the headlights are on, and the interior lights dim. I located a button on the dashboard that has a light inside, and I simply spliced a wire into a harness. When power is provided on this line, the gauge will dim to 30% brightness.

This is the is the best possible picture I could get of the fuse box, due to it’s difficult location. You can see on the bottom in the center, one of the add-a-circuit fuse taps installed. You can see it has a blue and red fuse mounted in it at a 90 degree angel to all the other fuses. 

Despite this sounding simple, it took 4 hours, because of the inconvenience of the location, and because I wanted to make sure everything got done properly. This being said, I did not use any of the plastic splice connectors. For all of my splice connections, I first cut all the existing wires, stripped them, and soldered them back together with the spliced wire, then slid a piece of heat-shrink tubing to keep the connections safe. This is the best way to insure a reliable connection. Any connector that relies on friction, like butt-splice connectors, and quick-splice connectors, can be unreliable, and it’s possible that a proper connection can never be made.

We will talk about the place to obtain a reading in Part 2, since I did not install the sensor today.

Today’s Progress

Today, I got the gauge mounted, and got all of the power connected properly to it. Now, it turns on and off with the car, and will dim if the headlights are turned on. It doesn’t display the actual boost pressure yet because I did not get a chance to hook up the sensor for it, which will need tapped into the air system under the hood. That will be a job for part 2, but for now, enjoy a nice video of the gauge mounted and running! Sorry for no audio. I had the radio on and don’t want to kick loose a copyright violation.

Thanks for reading, and as always, I encourage you to join my site, and comment your thoughts! Hope to see you again soon!

This Post Has 2 Comments

  1. Andy

    That looks sick dude!

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