Converting a Cabin Light to Led and Voltmeter!




Introduction: Converting a Cabin Light to Led and Voltmeter!

The cabin light in my wife's Hyundai trajet is super old school as in stupid incandescent lighting. I urged her to let me upgrade it with led lights. Upon seeing me get to work she suggested I put a voltmeter I have always wanted to install into her car.

This instructable is dedicated to the new sense of upgrades in my wife with respect to her car (hopefully there will be more such life changing events).

Step 1: Removing the Cabin Light Fixture.

Four 10mm bolts hold the fixture in place. Once out I took it inside the house to do some soldering!

Ps: the wife has her eyes fixed on me before getting to solder her cabin light fixture.

Step 2: Installing the Leds.

Some soldering and some clever fitting.. The leds are now in place.

Step 3: Removing the Oem Clock.

The clock never worked properly for years. Removing it was a guilty pleasure... Almost like popping a zit. In the void created I will place the voltmeter.

Step 4: The Voltmeter.

This neat little unit will easily tell her if her battery is weak or the alternator has failed. It cycles between pure voltage reading and the % charge based on stage of charge reading. It needs to be programmed first prior to being used on a battery chemistry.

Her car tends to eat up alternators but later on I found out the Bogus car electrician was at fault. Hence the reason I'm excellent with electrical work and a happy coincidence at that! After much debate over the years she has let me upgrade the electricals. Little by little I will make her car super excellent! I shall work my charms.

I had to cut the old clock visor since it was polarized. I used evostik to attach the voltmeter behind the visor.

Step 5: Reinstallation.

The fixture went back in smoothly. Now to do a commissioning test.

Step 6: Completion.

Viola! Proper lighting and a helpful voltmeter. Now we are ready for the road!

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    3 Discussions


    3 years ago

    all you gotta do is apply 12v to the meter, don't worry about current, you can buy meters on eBay.


    4 years ago

    Just wondering what LED's you are using? How are you controlling the current to the LED's? Are you just using a resistor are you using a controller? Where did you find the LED's that you are using? That doesn't really seem like a volt meter. What is it measuring?



    4 years ago

    Sorry my friend, that voltmeter looks like it is just about useless... or your car's battery is dead..

    On the workbench it shows 47%. Don't know what that's powered by, and it's not important.

    Installed, the voltmeter shows 57%.

    57% of what?....the battery voltage? the charging voltage??? They are different.

    If your BATTERY is showing a 57% charge it has only got a workable voltage of 6.84 volts . A 12 volt battery, is usually considered dead at 8 volts or less

    If it is 57% of the CHARGING VOLTAGE, of say 14 volts (the average charge),

    THEN YOUR CHARGING VOLTAGE IS is only 8 VOLTS. [Oy Vey! ..the math!]

    You are not going to be charging a 12 volt car battery, with ONLY 8 volts.

    Now I have been working on my own vehicles, for better than 60 years and was an electronic technician before I retired.

    My OEM dashboard voltmeter was acting very strange, and showing a reading of 20+VOLTS!!! I knew this had to be some glitch with the car's computer, so I bought a direct reading LED voltmeter. It proved me correct. The OEM gauge read 20+ volts while the LED voltmeter hooked up (outside the computer circuit,) still showed my normal charging voltage of 14.5 volts. (AT 20 VOLTS I WOULD HAVE BEEN BURNING OUT 12 volt LIGHT BULBS LEFT AND RIGHT!)

    There's plenty of them on eBay (Search led digital voltmeter) for about a dollar. or so... you can get them in a number of colors. These will read the exact battery voltage when the key is off, and the charging voltage with the engine running. and there will be no math needed, to interpret their readings. Don't worry about draining the battery by leaving it lit. It's tiny current draw would take quite some time to drain the battery. Mine has been running now for almost 6 months, and it hasn't dropped 1/10th of a volt.

    Great 'ible otherwise.

    LEDs in color.jpg