Headlights can be optional equipment on a tractor. But what’s not optional, is that headlights perform well when needed. Working in poorly lit conditions can be fatiguing, frustrating, or even hazardous. If you’re like me, you’re a tractor enthusiast and enjoy using your equipment. Having a good lighting system on your equipment only means there are more hours available during the day, or night, to have fun!
Last fall while mowing the lawn after sunset using my Wheel Horse GT-1142, it became too dark to see well. Thankfully the garden tractor is equipped with dual headlights. After turning them on it was much easier to see, however, making out small details such as the line between the cut and uncut grass was nearly impossible. It appeared as though the headlights provided enough light to make it possible to see the cut line, but the color of the light just didn’t provide enough contrast to discern this detail. I simply drove back and forth across the yard hoping that I hadn’t missed any spots. I was dissatisfied that I could not see well enough to reliably finish mowing the lawn.
The GT-1142 garden tractor is equipped with the original equipment halogen sealed beam PAR 36 4411-1 round lamps, which are rated 35 watts at 12 volts. My first inclination was to replace the two stock 35 watt lamps with 50 watt lamps; however, that would increase the total current draw from the electrical system from 5.8 amps to 8.4 amps. Perhaps the tractor’s electrical system was up to the task of powering 50 watt bulbs, but I figured there must be another solution using the latest LED lighting technology.
There are very few options for replacement LED PAR 36 lights, however, searching the Internet revealed an offering from Grote Industries, Madison, Indiana (http://www.grote.com
). Grote’s Trilliant® 36 LED WhiteLight™ conversion bulb has the form factor of a PAR 36 lamp, but uses LED’s instead of an incandescent bulb. Six surface mount LED’s and the electronic circuitry is sealed into an aluminum housing with potting compound. The housing is powder coated gloss black and incorporates cooling fins and the combination Faston spade / screw-on electrical terminals on the back side. The front side of the housing is covered with a clear polycarbonate cover that contains six integral lenses that casts what is called the TractorPlus™ beam pattern, which is said to provide three times more usable light compared to traditional PAR 36 bulbs. A clear lens-less cover is also available.
Figure 1: Trilliant® 36 LED WhiteLight™ Conversion Bulb with the Lens removed
I contacted Grote and inquired about the Trilliant® bulbs and learned that they were in their initial production run and not yet on the market. However, after some negotiating, I was provided a pair at no charge in exchange for this summary of their performance versus an incandescent bulb.
The photo and test session started with taking beam pattern photos at night of the standard original equipment incandescent bulbs. Figure 2a shows the results of the standard bulbs installed in the Wheel Horse and is the baseline for this comparison. The light beam pattern seems adequate for yard work and the light color is warm yellow, typical of halogen incandescent bulbs.
Next, the Trilliant® bulbs were installed and they are direct replacements for PAR 36 incandescent bulbs. On the GT-1142, they simply slip into a sheet metal housing and are held in position by a metal tab secured with a bolt. The electrical terminals on the back of the lamp easily accepted the Faston spade terminals of my wire harness. The Trilliant® bulbs were installed in about five minutes.
After turning on the Trilliant® 36 LED WhiteLight™ conversion bulbs, the first thing I noticed is the color of the light. The Trilliant® bulbs cast brilliant white light, similar to that of automotive HID headlights (Figure 2b). I found the white light to more closely match natural light, which brought out the true colors of illuminated objects and therefore details were easier to discern. Straining to see is one activity that can lead to operator fatigue, but this will certainly be less of an issue with the bright white light from the Trilliant® bulbs.
I next noticed the much larger beam pattern that the Trilliant® bulbs provided. You’ll see in Figure 2b below that the Trilliant® light beam pattern extends both farther and wider compared to the incandescent bulbs in Figure 2a. If you study Figure 2b, you’ll notice the landscape behind the swing set and three trees to the right that are visible; you can’t see these details in Figure 2a. The bigger beam pattern is very beneficial because it illuminates more of the work area ahead and makes it less necessary to have to steer the tractor to the left or right to see what’s in that direction.
Figure 2a: OEM Incandescent Bulbs
Figure 2b: Grote Trilliant® 36 LED WhiteLight™ Conversions Bulbs
An additional advantage of the Trilliant® bulbs is that they draw less current than the stock 35w incandescent bulbs. Grote’s product information sheet states the lamps have an operating voltage from 10v to 30v. I measured the current draw for each Trilliant® bulb and that was 1.3a at engine idle speed and 0.8a at engine high speed. For comparison, each incandescent bulb drew 2.4a and 2.9a at idle and high speed, respectively. The LED’s lower current draw could be an asset if the lights are used as auxiliary lighting on equipment with marginal alternator capacity.
The Trilliant® bulbs contain internal circuitry to regulate the amperage drawn by the bulbs based upon the supplied voltage. One observation about the LED’s current regulating circuit is that when it entered the high-voltage range, the light output of the LED bulb dropped a little bit. I don’t have any method to measure the difference, but I will describe it as minimal and hardly noticeable to the average observer. The difference is barely discernable in pictures, like in Figure 2.
Figure 3: Wheel Horse Hood with LED’s Installed
One issue with the Trilliant® installation, particular to the Wheel Horse garden tractor, is that the lamps are installed a few inches behind the front grill of the hood and the open space between the front grill and the lamps is filled by a plastic bezel. This bezel interferes with the light beam emitted by the Trilliant® bulb. In Figure 3, the right side bulb (reader’s left) is shown with the stock headlight bezel installed and it obscures the top and bottom LED’s of the cluster, which is about 1/3 of the light output. In Figure 3, the left side bulb (reader’s right) is shown without the bezel and all six LED’s are clearly visible. The degree to which this interference changed the light pattern wasn’t measured.
The pictures in Figure 2a and 2b were taken without the bezels installed to provide the best possible light pattern, but this particular design of the Wheel Horse tractor hood does still interfere with the light beam of the Trilliant® bulb. The rectangular opening of the front grill blocks some of the light, but again, I don’t have any method to measure the impact. A Grote product information sheet (located online here http://www.grote.com/prodcat/attachment ... oSheet.pdf
) shows nighttime comparison photos of the Trilliant® bulb versus an incandescent bulb in a farm tractor where the installation doesn’t interfere with the light pattern and the difference even more dramatic than that shown in Figure 2a and 2b.
I had fun driving around the yard with the Trilliant® bulbs turned on after the photo session. I was truly impressed with the brilliant white color of the light and the large beam pattern which illuminated a good section of the yard. I have to admit that I was a little self-conscious with these headlights blazing so brightly. I intentionally avoided steering the tractor toward any of my neighbors’ windows for fear of either startling them or making them upset. They must have already thought I was crazy for being out as late as I was!
In conclusion, the Grote Trilliant® 36 LED WhiteLight™ Conversion Bulbs outperform, by far, a standard incandescent PAR 36 bulb. The Trilliant® bulbs output a whiter light which helps better illuminate fine details and reduce fatigue. And the beam pattern is much bigger which is safer and helps get the work done faster. I have to agree with Grote’s statement: “More usable light.” I was not disappointed in any way by these bulbs, and with a claimed service life of 40,000 hours, I don’t think I will be any time soon.
More nighttime photos are available here: http://s52.photobucket.com/albums/g7/bp ... eadlights/