Toyota Sienna Forum - banner

No high beams

28852 Views 13 Replies 8 Participants Last post by  DarynDJS
Curious if anyone had ideas on what could cause this. I recently bought an 08 LE in which everything works except the high beams.

When I pull back or push forward on the headlight control, I see the blue high beam light appear on the instrument panel but the actual bulb doesn't turn on. The low beams and turn signals work fine. I don't have DRL lights as best I can tell. There's no "auto" DRL toggle on the headlight control & the #2,#3,#4 DRL relays in the under hood fuse box are empty (hope that normal?)

No luck after replacing the bulbs and the fuses look ok. I heard the emergency parking brake might affect this, but when I push it on/off, it didn't turn the high beams on.

I've tackled some DIY repair (exhaust, radiator) before but haven't troubleshot anything electrical before. Some tips would be greatly appreciated!
1 - 1 of 14 Posts
Just a warning... The only time in my life that I lost two headlight bulbs at the same time was when an alternator needed to be replaced. The internal voltage regulator was spiking. In a way, the dead headlights served as an excellent 'heads up' that a problem was brewing before it manifested itself as an overvoltage damaged electronics module or something else expensive.

High beam bulbs can become very vulnerable over time. Their use as DRL at half voltage interferes with the halogen cycle that is supposed to redeposit tungsten back on the filament and maintain it's integrity. Instead that tungsten deposits on the inside of the glass making it dark, and it leaves the filament with thin spots. Those thin spots are then susceptible to damage if the voltage rises higher than it should, and both bulbs blow at once.
Thanks for that heads-up. My 05 with DRL just had both high beams blow - and I think one of the microfuses. I swapped all relays with my 04 (one at a time) and confirmed they were OK, but then found the bulbs blown. If this new set goes soon, I'll know to take a look at the alternator.
1 - 1 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.