Possible to dim gauge lighting

diungerich

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2007 Glastron GT205 with Faria gauges.

So far I'm not out at night very often. But when I am I've found that I'd really like to dim the gauges way down to keep from affecting my night vision. Anyone know how much of a pain it is to setup a dimmer dial on these?
 

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lmuss53

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The gauges in my old starcraft all ran off one hot wire, it ran from gage to gauge. I put a simple on off switch in that circuit to turn them off while running. If you have that wire I don't see why you couldn't put a pot in to dim them some.
 

gm280

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Yes you can adjust the brightness of lighted gauges. First you need to know if the lights are LED or filament type. Most likely filament type but these days LEDs are everywhere. You can install a switch so you can install a mere resister inline and when you want a bright gauge lights, you can short out the resister, and if you want the gauge lights dimmer, you can switch the resister in. Kind of how your vehicle gauges work. So you need to know how much current your gauges draw. If you have a meter with a current option, you can see how much current the gauge lights draw. Then selected a resister to dim them to where you want them to be and install a resister to set that level. But make sure you use the proper wattage resister also. I know this sound complicate but in reality easier then you would think. Another option is to install a diode inline. As you install a diode, the voltage drops by about .6 volts. So it may take two or more to get to where you want the level. Just make sure you install the diodes in the right direction. You will know if you install it wrong, because no lights will light. So simply switch it around. And keep adding diodes until you get what you want... A good diode is a 1N5400 series (1N5400, 1N5401,etc.). They will handle 3 amps. I can't see your lights needing more current then that. And if the current is less then an amp, you can find 1N4000 series diodes will work perfectly. Easy Peasy... JMHO!
 

Alumarine

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One thing I do is put red nail polish on the bulbs if they aren't red already.
Helps preserve night vision as well.
 

Scott Danforth

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My last 3 boats have come with a switch with 2 positions, one much brighter than the other.
 

diungerich

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Based on the look of the lighting, I'm pretty darned confident it's incandescent bulbs. I'll have to check out the wiring. Shutting off is fine, but I'd really like a small dial to just scale it back when desired. We'll see.
 

tanker1983

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I had the same issue with my Faria gauges on my Glastron DX235 and did not want to mess with the wiring or have to cut into my dash. What I did was cover the bulbs with these silicon covers for gauge bulbs.

http://www.ebay.com/itm/AUTOMETER-32...0b1357&vxp=mtr

This picture shows the gauges much brighter than they are now. They are actually a nice muted blue and they work perfectly.
10552634_802947293069830_3892177926227892508_n.jpg
 
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lmuss53

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I'd try to find a volume control an old radio, look at the side and see if it will carry your amperage, I would look for something up to about 7 or so amps.
 

gm280

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I'd try to find a volume control an old radio, look at the side and see if it will carry your amperage, I would look for something up to about 7 or so amps.

Imuss53, Are you suggesting to use an old volume controller out of an old radio for a light dimmer? If so, don't. It will not work because the resistive material isn't designed to carry the current for such light dimming. It may allow one light to be controlled for a few milliamps, but a string of lights will certainly up the current and unless the potentiometer is capable, it will smoke, and pretty quickly too. Usually most potentiometers are mere 1/2 watt or there about, and those in newer radios are not even that capable because they usually bias other circuits to control the volume. And if you sum up the current for each of the gauge lights, they will certainly exceed 1/2 watt. Remember, it is current times voltage to yield wattage. JMHO!
 

lmuss53

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That was my suggestion with the qualifier that it has to carry the current. I'm just trying to help the man find a way to get this dimmer in.

I've got my Ohms law down fairly well, just wasn't sure what went through those kinds of switches.

A lot of vehicles have a dimmer control for the dash lights separate from the headlight switch, maybe a trip to your local "U pull it" junkyard for one of those.
 

lmuss53

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gm280

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Imuss53, those typical light dimmers that are specially made for such a job will work. But they are not the usual potentiometer setup, but actually rheostats. The difference being rheostats are typically wire wound to handle the current while potentiometers are not. When you move the dimmer controls you can feel a little rough feeling to it and that is because the wiper is sliding across the wire windings. If a person can fit one of them into their dash panel layout, have at it. They will work if wired up correctly. :thumb:
 

lmuss53

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Thanks, I didn't know there was a difference I guess I just thought the smaller pots had finer wiring. Isn't a rheostat also a potentiometer though?
 

gm280

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Thanks, I didn't know there was a difference I guess I just thought the smaller pots had finer wiring. Isn't a rheostat also a potentiometer though?

Imuss53, in answer to your question, YES and NO. Yes in the fact that both a rheostat and a potentiometer do basically the same thing, but no because usually the correct terminology in a current controlling device is usually wire wound and called a rheostat while a voltage controlli8ng device is called a pot or potentiometer, or even a variable resistor. Some good You Tube videos try to explain the difference if you care to watch. Just understand that if you are going to pass a huge amount of current through such a device, it has to be capable of handling the current without burning up. Potentiometers are usually in the K-ohm ranges meaning thousands of ohms, So the only portion of the pot to control the lights would be at the very end of its travel (or the very beginning how ever it is connected up). The rest of the circular travel would virtually have zero effect on controlling the lights. But rheostats are usually in the lower ohm ranges to control current better and therefore used for dimming efforts. Just think ohms law and how a few ohms can have a huge difference on current supplied. The lower the ohms the higher the current and vis versa. JMHO!
 

sam am I

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funk6294

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After redoing my dash I had the same issue as the OP with being blinded at night. To solve this I ended up putting in a PulseWidthModulated dimmer. It ran me about 35 bucks including shipping and does a great job dimming the dash lights. It works on incandescent bulbs, but is also the recommended method for dimming LED bulbs (future plan). So if you have or want LED bulbs it's the way to go. The only issue I ran into during the install was the factory gauges used a common ground for the bulb and the gauge which is a problem because the PWM occures on the negative side. I solved this by purchasing new light sockets that had a wire for both positive and negative (needed 12 sockets which set me back about $20 on Amazon). So after $55 and about an hour of wiring I have gauges that can be dimmed to all the way off. šŸ˜ƒ
 

funk6294

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i just took a look on eBay and if you were looking for just a dimmer here is one and the knob is labeled as such to boot! Btw, this would be MUCH easier than the route I took. Just put inline on the positive side going to the gauge lights and your done. No need for new sockets or a ton of wiring. I must be just a glutton for punishment....
 
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