How to Dim After Market Gages?

[JohnHaggerty]

What's the best way to dim after market gages? They are already hooked up to the dimmer that controls the gage cluster. They do dim with the others, but are still to bright. Changing bulbs seems like the thing to do. Any experiences here?



Thanks!

 

[lil red cummins]

The best way to dim the light is to put a resistor in series (in line) with the hot wire going to the light.



The resistor value you use depends on what type of lamp is in the gauge. if you have an old style incandescent lamp, you will need a higher wattage resistor, say 1/2 to 3/4 watt. the actual resistance needed would be somewhat trial and error depending on what light level you prefer.



if you have an LED style lamp, they use much less power, so a 1/4 watt resistor would be large enough. as for the resistance value, again, this depends on your preferred level of light.



if you do not have access to different values of resistors for trial and error, this makes the job much more difficult to "trial and error".



if you want a GUESS starting point, and this is purely off the top of my head, for the incandescent lamp, try putting a 1/2 watt 1000 Ohm (also known as 1K) resistor in series with the hot wire going to the lamp. this may have no effect at all or may not let the light come on at all. you also need to be aware that the resistor will get warm. you will need to monitor the resistor temperature by periodically touching it with your finger for about 5 minutes to see how warm it gets. if it gets too warm to touch, you will probably need to go to a 3/4 watt resistor of the same ohm value.



for the LED style lamp, start with a 1/4 watt 475 ohm resistor. chances are, this resistor will not get hot because the standard LED only draws 20 milliamps. that is . 02 amps.



radio shack is your best source for resistors.



higher value resistance will give you a dimmer bulb. (10,000 ohms=10K and is HIGHER than 1,000 ohms=1K).



it the bulb is too bright, try a resistor with double the resistance value. if the bulb is too dim, cut the value in half and try again



the actual value you end up with may be as low as 10 ohms or as high as 10,000 ohms. I am just not sure what to tell you beyond this.



good luck.



Jim

 

[mcurtice1]

When I installed my gauges, I got a separate dimmer switch from Autometer for the gauges. It works great as i can adjust it at will to match the gauge cluster.

 

[AWise]

If you want it to be adjustable, buy a potentiometer/rheostat (basically a variable resistor). you may need to put in a small resistor & potentiometer depending on the wattage.

 

[seafish]

so is ther no way to hook up the gauge lights to behind the oem dashboard dimmer switch?? or is it just too complicated??

 

[CDonaldson]

He said he has them hooked up to the factory dimmer switch seafish.



What kind/make of gauges do you have John?



I have the ISSPRO EV2's, ISSPRO offers a remote dimmer, it conncets to the factory dimmer but then allows further dimming, real nice to dim them down.



I believe you can use the Autometer dimmer with the Classic ISSPRO gauges, and with DiPricol's as well - the ones with bulbs.



The newer led gauges work well with/need the other ISSPRO dimmer like I have for the EV2's.



CD

 

[seafish]

He said he has them hooked up to the factory dimmer switch seafish.

CD

ooops. . got that now... so by putting in a resistor, one can dim them even more, but they continue to be adjustable by the factory dimmer. Thanks.

 

[CDonaldson]

As was also mentioned above, install a potentiometer (variable resistor). That is what the ISSPRO dimmer switch kit consists of tunable potentiometer. You can get one at Radio Shack, or you can just get one from ISSPRO for the led type gauge bulbs or from Autometer for the bulb type gauges.





CD

 

[JohnHaggerty]

Still Thinking

As previously mentioned, I did hook up to the OM dimmer circuit. It was easy and covered about spring of 08 in a TDR magazine.



I have DiPricol's. I like them, but just too bright. The Boost gage could have been the lower scale version, but I'll live with it.



So it seems a resistor or potentiometer (sp?) is the way to go. If I go resistor, wattage becomes an issue (guess). I assume wattage for the potentiometer is not an issue. Resistor seems to be the cleaner install, but risks fire.



I'll probably go the potentiometer route and tie it up under the dash.



Thanks for the replies.



"Drive it like you stole it!"



John

 

[HOBrian]

A cheap fix is to just use a sharpie and color the bulb to dull it down.