923a2 wiring voltage question

[mcmud]

I found a company that wants to do some work with me on lighting but it's all 12 volt stuff. I read that it's possible to hook the ground on the first light to the positive on the second and make the 12 work on 24. What's the down side to that? I have been trying to find in line transformers but to no avail. Is there any? All that I have found are the bigger box types. Thanks everyone!

 

[juanprado]

I asked the same question recently.
Yes, it will work 12v but what I learned is when one light or fixture goes out everything else is not powered like those old pesky Christmas tree lights. Will make troubleshooting a lot of fun!

 

[mcmud]

Did the lights burn out after the full life cycle or was the voltage too much? If they have a normal life I wouldn't mind, I can yes both components really easy

 

[KsM715]

Keep looking for 24V lights. they are easy to find once you know where to look. On a simple bulb you can hook two in series to operate on a 24v like you said but doing that with headlights with high and low beams is going to be more confusing than its worth.

*edit* I miss read your post. what type of lighting is this company wanting to work with you on? By the way you dont need transformers, you need resistors. If you find the proper resistors (correct wattage and ohms) to drop the 24V to 12V it might work but realize that when voltage goes down amperage goes up.

 

[mcmud]

I was going to do hid lights. The ones on the truck now might as well be broken they are so dim! I don't need the high and low, just the low. I am talking with the manager, if he's willing to try it and see how his product performs, could be interesting!

 

[quickfarms]

It may not work with led lights.

The 24 volt bulbs are commonly available at semi truck parts houses. Some older trucks and construction equipment is 24 volt.

 

[mcmud]

I have somw led fog lights that work amazing. I just was hoping to get the brightness of the hid. I guess I'll have to try it and post the results

 

[MtnSnow]

They still have pretty good life when hooked up in series so they can work on a 24v system but like mentioned when one fails the other will not work until the failed one is replaced.

 

[mcmud]

I'll just have to get two pairs I guess so I always have a spare! I'm excited to see how they work

 

[idbankrman]

I don't know the wattage of the standard 24volt headlight on low beam but a 12 volt headlight is usually about 160 watts therefore the current is a little over 13 amps. So if you need 13 amps in your 12Volt light inserted into your trucks 24 volt system you would need a power resistor in series with it of about .9 ohms. This resistor will get hot and put out the same watts as the headlight. This is why its really a bad idea. Probably best to stick with a 24volt headlight. The equation here is Voltage =Amps X Resistance. This means that a 24 volt headlight putting out 160 watts only uses around 7 amps. This allows the wiring to actually be a smaller gage than that in a 12 volt system.

 

[mcmud]

The lights would be 35 watts and about 4.5 amps approx. So that would be 35=4.5•x, making the resistance about 7.8. If I ran 14 gage wire would that still be sufficient?

 

[MtnSnow]

http://www.viaircorp.com/OnRoad/VIAIR_wiregauge_chart.pdf shows what size wire to use for distance & amp load for both 12v and 24v systems and yes 14 gauge will work if the runs are short enough

 

[doghead]

I don't know the wattage of the standard 24volt headlight on low beam but a 12 volt headlight is usually about 160 watts therefore the current is a little over 13 amps. So if you need 13 amps in your 12Volt light inserted into your trucks 24 volt system you would need a power resistor in series with it of about .9 ohms. This resistor will get hot and put out the same watts as the headlight. This is why its really a bad idea. Probably best to stick with a 24volt headlight. The equation here is Voltage =Amps X Resistance. This means that a 24 volt headlight putting out 160 watts only uses around 7 amps. This allows the wiring to actually be a smaller gage than that in a 12 volt system.

In what application?

The H1 lamp was the first tungsten-halogen headlamp light source. It was introduced in 1962 by a consortium of European bulb and headlamp makers. This bulb has a single axial filament that consumes 55 watts at 12.0 volts, and produces 1550 lumens ±15% when operated at 13.2 V. H2 (55 W @ 12.0 V, 1820 lm @ 13.2 V) followed in 1964, and the transverse-filament H3 (55 W @ 12.0 V, 1450 lm ±15%) in 1966. H1 still sees wide use in low beams, high beams and auxiliary fog and driving lamps, as does H3. The H2 is no longer a current type, since it requires an intricate bulb holder interface to the lamp, has a short life and is difficult to handle. For those reasons, H2 was withdrawn[SUP][31][/SUP] from ECE Regulation 37 for use in new lamp designs (though H2 bulbs are still manufactured for replacement purposes in existing lamps), but H1 and H3 remain current and these two bulbs were legalised in the United States in 1993.[SUP][32][/SUP][SUP][33][/SUP] More recent single-filament bulb designs include the H7 (55 W @ 12.0 V, 1500 lm ±10% @ 13.2 V), H8 (35 W @ 12.0 V, 800 lm ±15% @ 13.2 V), H9 (65 W @ 12.0 V, 2100 lm ±10% @ 13.2 V), and H11 (55 W @ 12.0 V, 1350 lm ±10% @ 13.2 V). 24-volt versions of many bulb types are available for use in trucks, buses, and other commercial and military vehicles.
The first dual-filament halogen bulb (to produce a low and a high beam with only one bulb), the H4, was released in 1971 and quickly became the predominant headlamp bulb throughout the world except in the United States, where the H4 is still not legal for automotive use. In 1992, the Americans created their own standard for a bulb called HB2/9003, almost identical to H4 except with more stringent constraints on filament geometry and positional variance, and power consumption and light output expressed at the US test voltage of 12.8V.
The first US halogen headlamp bulb, introduced in 1983, was the HB1/9004. It is a 12.8-volt, transverse dual-filament design that produces 700 lumens on low beam and 1200 lumens on high beam. The 9004 is rated for 65 watts (high beam) and 45 watts (low beam) at 12.8 volts. Other US approved halogen bulbs include the 9005/HB3 (65 W, 12.8 V), 9006/HB4 (55 W, 12.8 V), and 9007/HB5 (65/55 watts, 12.8 V). All of the European-designed and internationally approved bulbs except H4 are presently approved for use in headlamps complying with US requirements.

 

[idbankrman]

Watts = Volts X Current. If the bulbs are 35 Watt bulbs then the current in a 12 volt system is 35/12 or 2.92 amps. So to drop the 24 volt system by 12 volts in your headlight circuit you will need a resistance of 4.1 ohms in series with your headlight bulb. Of course the bulbs resistance and current draw are different depending on which beam you are using so the high beam and low beam circuits will each have a different resistor in series with the them. You can probably order high current resistors from radio shack or some other supplier but ordinary electronic resistors will not be able to take the high current required here. Also the resistors will probably need a heat sink and shield since they will get hot.

 

[mcmud]

Just and update on the lights. I have the HID lights installed, happy I went with the 35 watts and not brighter. I pull up behind cars and try to stay a nice distance but it still looks like daytime in their car! I ended up bypassing the main switch which i wanted to use initially. I pulled a wire off a single positive terminal and ran it to a fuse block, then installed a temporary switch until i find a switch panel i like. I pulled from there to the lights, disconnected the main low beam and taped it off then ran the power wires through there for my lights. I am very happy with the way they look. The combination of those with the three led fog lights is very nice to have.