toyotas and automatic headlight sensor

Ok an update: Worked on this a few hours yesterday and determined there was no choice but to connect to the hazard light wire to see the lock/unlock alarm flashes when set to auto-HL. The 'After the relay' PL output wire I tested came out to be moot. That wire is grounded at all times. Seems it switches from ground to 12v when the PL relay gets the (-) signal from the HL switch or (-) pulse from the alarm. After testing the hazard wire, I figured the (-) 1 sec momentary PL lock/unlock pulse from the alarm is good enough because if the pulse was any longer than that, the hazard lights will flash 2x from a 1x pulse. That would suck. Well at the end, I decided to connect the alarm PL output wire to both the hazard and PL wire on this car. Diodes are used to isolate the hazard and PL circuits. I did this for the remote start PL flashes as well. Wiring it this way worked out better than expected. The PL wire from the alarm has a steady 2sec 12v output between pulses so the car parking lights just stays lit for the 2sec duration while the hazards flashes 3x, ten pauses and then starts the cycle again. Really looks cool and different. By just looking at the flash scheme, you definitely will know the car is remote started. Of course, since the PL lights don't work when set to auto-HL, the hazard pulse timing is synchronized with the alarm lock/unlock pulse. So, this ends my Sunday morning write-up...

Good to hear you found a suitable solution.  As cars get newer and technology gets more advanced installers run in to these issues more and more.Kevin Pierson

I have run into this problem with alarms on the prius, camery, sequoia, sienna... and have had to use the positive wire for parking lights. No problems yet.

This is a little late but on my '05 Tacoma if I leave my headlight switch on mine will not flash either.  The problem is that the body ECU controls this function and inhibits this from happening.  The only way to get around this (at least as far as I can tell) is to isolate the circuit so that the ECU does not intefere.  This did not bother me so much so I did not go that route.  I just remember to turn the switch off.  Also, since I have a two-way alarm (Autopage RS-860) my key fob shows the arming status.Pioneer AVIC-Z1, JL 8W3V2, XR650CSi, 300/4, 250/1, Bluetooth, XM, A/V switch, Backup Cam, Autopage RS-1000

sarcomax wrote: I have run into this problem with alarms on the prius, camery, sequoia, sienna... and have had to use the positive wire for parking lights. No problems yet.

Hey sarcomax, As I understand it, the (+) PL wire rest at ground at all times. How did you get around this and why didn't you use the (-) PL wire from the headlight switch harness instead? Where did you connect the (+) PL wire on the Sienna anyway? Thanks.