LED's, step 6: the high beam indicator and flash function:
Step 6: Here is how you fix the high beam indicator:
Here is the list of items that you will need to get your high beam indicator working again:
• One male H4 pigtail (mentioned in my previous email)
• One 12V Relay and Socket
https://www.amazon.com/dp/B007JPPQH6
◦ Any 12V relay and socket should work except for “NC” (normally closed) type relays. Relays and sockets should readily available at any auto parts store
• One resistor (this is where you get to make a decision)
◦ I would suggest a 10ohm resistor capable of handling 5 watts, similar to
https://www.amazon.com/dp/B0087ZE402
◦ The resistor can have a resistance anywhere from 1 to 50 ohm (I don’t recommend less than 5 ohm or more than 30). The resistance you choose will determine how bright your high beam indicator light is. A 5 ohm resistor will make the indicator about as bright as it was with the original headlights. Increasing the resistance to 10, 20 or 30 ohms will reduce the brightness of your high beam indicator by roughly 10, 20 and 30% respectively. Some people find that the high beam indicator is brighter than necessary with the original headlight setup.
◦ The catch with this resistor is that, due to the Toyota wiring setup, the resistor gets a full 12 volts when you use the “flash mode” of your vehicles headlights (pulling the high/low beam lever towards the steering wheel briefly). If someone were to hold the lever in flash mode, the resistor would get very hot and burn out. If you want to avoid this possibility, the resistor must be able to handle the full 12 volts indefinitely. In order to calculate what size (wattage) of resistor is necessary, you must take the voltage squared and divide it by the resistance that you choose (P = V2/R) P = Power in watts, V = voltage, R = resistance in ohms. If you choose a 10 ohm resistor and assume an operating voltage of 14.4 volts, the resistor must be able to handle at least 20.736 watts. A 10 ohm, 20 watt resistor (similar to
www.amazon.com/dp/B0087YHQLW) would probably be very safe. If you aren’t concerned about someone holding the flash mode on for more than a few seconds at a time, I think a 10 ohm 5 watt resistor would be more than adequate. In most cases where the flash mode is only ever used for a quick flash, a 1 watt resistor would probably be just fine. The system will operate just fine with no resistor in place until you try to use flash mode, at which time you will blow both headlight fuses.
Terminals 85 and 86 are the “activation” side of the relay and terminals 87 and 30 are the “switched” side of the relay. When you apply 12 volts across terminals 85 and 86 (in either direction), the relay closes the switch connecting terminals 30 and 87. You should hear the relay click when you apply power to the activation terminals.
The common (+) terminal of one of your truck’s low beam plugs must be connected to one terminal on the activation side of the relay AND one terminal on the switched side of the relay. The high-beam terminal of must be connected to the other terminal on the activation side of the relay. The low beam terminal must be connected to the other terminal on the switched side of the relay with the resistor connected in-line.
There's a lot of words in this section. Here's how to wire it:
On the low beam switch:
Common wire to relay terminals 86 AND 87 (printed on the relay itself. You will need a 24V relay!)
High beam wire to relay terminal 85.
Low beam wire to relay terminal 30 with the resistor in line.
I used a 25W 10ohm resistor on my 12V truck. For a 24V truck, operating at 28.8V, you could use a 10ohm, 90W resistor to be safe.
Here is my relay circuit.