Then, connect the power leads, via a fuse I used a single 30A fuse in my , but two separate 20A fuses would also work well to power picture B - if no fuse block handy, you can run a fused wire off the battery or off the engine fuse box as needed. B: New Relays and Fuse Block Connection C: Stock H4 Connector unused New H4 Connector Installed 2. Once the file is saved to your computer, it is yours for good. But before converting the harness, you may actually want to temporarily plug the switched power harness into your headlights to both verify that high and low beams work normally they should and if your high beam indicator lights or not. Likewise, if the dimming resistor is in the ground side of the headlights, you'll want to conenect the wiring harness ground wires the black wires off the two new headlight connectors to the dimming resistor instead of directly to ground, as described in the first Toyota case above. Best option is to only handle the bulb with some clean gloves or with the bulb wrapped in a clean cloth. Then insert the new resistor leads and solder it in place.
The factory tail lights bulbs are typically powered by standard incandescent lights that project a white color, and casts light through your red or amber tail light lens. So instead of Common-Low-High, you have Common-High-Low. I'll also add an override switch that will let me enable or disable the reverse light relay. Now test the harness and you should find that high and low beams work as normal and verify that the high beam indicator on the dash is now working. Check the connection and if necessary, scrape a little paint off where the wire connects to the body. This can cause problems like flickering lights, blown fuses, or worse.
Also, since the wires and switches controlling the turning on and off functions are on the ground side of the circuit, nothing damaging will happen if they somehow get accidentally grounded. A broken headlight lens does not only look unpleasant; it is also very inconvenient. Headlights not working If only one headlight is not functioning, the reason would be a burned-out bulb. My goal wasn't to make the absolute best lighting system money could buy. Probably a much better design than the H4, but I wanted to keep things stock. To do so, you need to change out the headlight connectors. I like my existing lights to work and do double duty.
This wire sends power to the low beam relay. The contacts should be flat and smooth, if not hit them with a thin file. Or, imagine tapping your brakes to slow down, but the other drivers do not realize the change in speed, because your brake lights or out. It can only go in one way and there is only one male H4 connector, so it is hard to get this step wrong! I carefully filed each pair of contacts until I had nice shiny metal on each one. Also, the diagram is drawn for clarity and does not reflect the physical layout.
The alternator is responsible for keeping the battery charged. For this type of setup, it is probably best not to try and integrate a headlight relay kit, since relays are mechanical devices are typically can't operate when a rapidly switching voltage. Another option would be to replace R1 with a small 12 volt light bulb, like a 10 watt festoon bulb like the dome light. And why did Toyota and many of the other Asian automobile manufacturer's choose to use switched ground wiring in their vehicles? For example if the power connection were to touch the case of the device, nothing would happen since it is not grounded. For the male-H4 input connector, , and pull it out the back of the connector. Likewise, on the female H4 output connectors, do the same with the Blue and Yellow wires. The connection shown in photo A supplies the control power to the two relays in the new harness.
All it takes is a small window of blurred vision to shift your attention elsewhere, and perhaps cause an accident. It is also easier to make systems where the chassis of the device is metal and grounded and then any internal ground connection can simply be made to that chassis, and that also helps shield out electrical noise from things like the ignition. I don't like the look and its more things to block air flow to the radiator and get damaged on the trail or stolen in the parking lot. Bulbs die out eventually, and that's normal. This can happen in a very short period of time. An incandescent bulb is really a variable resistance type of load.
This reduced power level is used to reduce glare to oncoming drivers and also to reduce the power load of the lights on the vehicle's electrical system. For some vehicles, an upgraded resistor may be required if there is too much current draw in the existing headlight system. So why are devices built like this? If you do happen to touch the glass, clean it off thoroughly with some isopropyl alcohol and a lint free cloth. Short circuit Electrical shorts are usually caused by moisture in the headlight housing or damage in the wirings. For example, if the harness were set up with a male 9004 connector to mate with the original 9004 connector in the vehicle, and if it had female H4 connectors for the new headlights, you could install the harness with no changes to the factory wiring, a true plug-n-play installation.
All the wires are run in protective looms, and everything is straight point-to-point connections, no splices or other mid-wire breaks. It includes an upgraded current limiting resistor suitable for use on late model vehicles which can pull more back current through the high beam indicator light. I found a lot of grease smeared all over the switch and this was probably the source of the problem. But if you see other than 0 volts across say the low-common terminals with the high beams on or the high-common pins with the low beams on,. This setup is conservatively rated to operate 100 watt bulbs. While most commonly they follow the , they can sometimes be wired such that the high and low bear connectors are swapped.
I run a set of Hella 550 fog lights on the front bumper and the headlights. With stock wattage low beams, I don't find I'm blinding oncoming drivers. But to be sure, you may clean your headlights at least once a week so that dirt will not accumulate over time. And since all the parts are interchangeable, you are not stuck with the bulb that came with the housing. Before, my high beams lit up down the road well, but left a huge dark void in front of the truck. Sorry, we only sell downloadable schematics, but you are welcome to print them on your own. If you find a loose wire, you can try re-crimping it or better yet, use a soldering iron and solder the wire to the connector.