If you have read the install guides on how to disable your DRL/AUTO ON via cutting a wire underneath your shift boot or rewiring wires from your relays underneath the Hood
you will notice that each have a flaw. If you disable the DRL's via underneath the Hood
you will successfully remove the DRL's without losing your high beams. However, it will not remove the AUTO ON feature. Secondly, if you disable the AUTO ON feature and the DRL's by cutting the wire beneath the shift knob then you lose your high beams. The way to remove both DRL and AUTO ON and not lose your high beams is relatively simple. Do both mods to the vehicle which are explained below:
DISABLE DRL AND KEEP HIGH BEAMS
Tools needed: wire cutters/strippers, soldering iron, electrical tape
1. Open the Hood
and locate the small fuse and relay box near the Intake
on the driver's side of the compartment. It will be rectangular and about 2" x 6".
2. Remove the lid from this box and inside you should find two 10 amp fuses and three relays, DRL relays #2, #3, and #4.
3. Pull out the three relays and set them aside in order. This is necessary to get enough space to flip the box over. You will notice five slots in each relay socket. If standing next to the car, the three closest to you will be vertical while the top two will be horizontal. You will notice that DRL relay #2 and #4 only have four pins and do not use all five slots.
4. Locate Pin 1 on the socket for DRL relay #2. Of the three vertical slots on the socket, it will be the one on the right. Locate this same slot on the socket for DRL relay #3.
5. On the side of the box closest to the side of the car is a tab. Press it so you can slide the box up and off its mounting tab.
6. Flip the box over and open the back cover. This may be a pain in the ass.
7. Locate the wires corresponding to the slots you found in Step 4. Remember that since you flipped the box over, they will appear to be in different spot now. Pin 1 on DRL relay #2 is a thick blue wire. Unfortunately, there are two thick blue wires going to relay #2, that's why its important to know where Pin 1 is. Pin 1 on DRL relay #3 is a thin red wire with silver spots.
8. Follow the thick blue wire coming from relay #2 to where it disappears into the wiring harness. Cut this wire about half an inch from here. You will need to tape over the end going into the harness with electrical tape. Strip the end of the wire for the section leading back to the socket for DRL relay #2.
9. Now take the red/silver spots wire you found in Step 7 and trace it to where it disappears into the wiring harness. About half way between the socket and here, you will need to melt the insulation off the wire. I did this using my soldering iron. DO NOT CUT THIS WIRE! The reason I say this is that the red wire has very little slack. If you cut it, its a serious pain in the ass to twist the ends back together.
10. Take the stripped end of the thick blue wire you made in Step 8 and twist it around your newly exposed wire.
11. Solder the blue wire to the red/silver spots wire and tape the joint with electrical tape.
12. Put the back cover on the fuse box, flip it over and reattach it to its mounting tab, replace your relays, and you're done!
If you think it will help you, click here to see a wiring diagram for the headlights for the Celica. This schematic will be referenced in the following discussion. Here is a drawing of the wiring changes made to do the DRL mod. I know its crude, but it gets the point across. Keep in mind that I drew the picture looking down at the box with the relays removed, so wires may appear to be in a different location when you have the box flipped over.
Why it works:
The mod described above works because you are causing one of the relays to receive power at a different time. DRL relay #2 is wired as normally-open, which means that unless the relay is receiving power, current will not pass through the relay. The two thick blue wires are connected to Pin 1 and Pin 3 on this relay. These wires have power at all times, even when the car is off. Pin 1 is connected to one side of a coil. Pin 3 is wired to the normally-open pin. The normally-closed pin is not used on DRL relay #2. The thick white wire with the blue stripe is connected to Pin 5, and routes power to the high beams. When the power at Pin 1 is allowed to flow across the coil, the relay switches, and the power at Pin 3 is allowed to flow to Pin 5, powering the high beams. This is where Pin 2 comes in. The one thin wire on DRL relay #2 is connected to Pin 2, which is the other side of the coil from Pin 1. Pin 2 is a ground controlled by the ECU. When the car is off or the parking brake is up, this ground is left floating, and the lights don't come on. Releasing the parking brake closes the ground and power flows across the coil, letting the DRL system turn on. Cutting this ground, or the power at Pin 1, or removing DRL relay #2, will disable the DRL system, but will also disable your high beams. The solution is in Pin 1 for DRL relay #3. Unlike #2, DRL relay #3 only sees power across the coil when the headlights turn on. This turns off the DRL system. Wiring Pin 1 on relay #2 to Pin 1 on relay #3 only powers relay #2 when the headlights are on, at which point the DRL's are disabled by another part of the system. This way, you disable the DRL's and keep your high beams. Good luck to anyone performing this mod and just remember to be patient. This mod is provided from http://www.ameritech.net/users/trdcelica/DRL.htm
TIME FOR THE SECOND MOD provided by http://www.celispeed.com/installs/drl/index.asp
DISABLE AUTO ON
This is a really easy mod to do. All you have to do is remove your shift boot, and ashtray, etc. Get the the fuse box, and unplug the harness that is on the lower right side of this picture. Once you have it unplugged, you will want to cut wire #17. This wire is Yellowish with a green stripe. You will want to cut it about a inch or two away from the harness connector, so you can reattach it if you sell the car, etc. Once you cut the wire, tape both ends off with electrical tape, and put everything back together.