Having issues with our 2007 ES 350. Low beam headlight (right side) goes out Intermittently. Took it to an independent shop who after checking the bulb and ballast thinks it may be the alternator. His opinion is that the alternator is not putting out enough juice. Any ideas ? Is there a way to isolate just the alternator to test ?

 

That's nonsense. You can test it with voltmeter, with the engine running put the voltmeter on + and - poles. It shoud be 13,7+V.

 

Get a new mechanic as he should have been able to do an alternator test and verify it.

 

Get yourself a $10 voltmeter to plug in the cig lighter port to monitor voltage while driving. Voltage at idle should be 13+ volts; ideally, voltage should be 13.5-14.5 (voltage will drop as heat builds up in the engine bay). Then perform a load test. Auto parts stores can do this free with the engine running. You can do one type yourself: check voltage at idle with headlights on high; fan on high (do not turn on the AC); and wipers on high - voltage should not dip below 12.6 volts, and the voltage difference with these components off should not exceed one volt.

 

This is not an alternator problem. You're headlight bulb needs replacing. The same thing has happened on my 2007 a couple of times. The low beam starts to intermittently fail, it comes back on and is good for awhile, then back to flickering. This is how these bulbs fail.

 

Yes, I agree; the problem seems to be more related to the bulb. Swap it to the driver-side and see if the problem follows.

 

If it were an alternator issue you'd be having more problems than an intermittent headlight. Anything is possible but I'd bet the headlamp needs replacing.

 

It's easy to replace the bulb yourself, and relatively inexpensive if you don't buy it at the dealer.

1. Remove the plastic HID socket cover by turning it counter-clockwise.

2. Remove the silver metal socket fitting attached to the braided cable by turning counter-clockwise about 45 degrees and pulling towards you.

3. There's a U-shaped set spring retainer that has kind of curled circle ends. This holds the bulb assembly in place by locking into notches on either side at roughly 11:00 & 1:00 on the housing. Pinch those two curled ends towards each other and pull them out and down to clear the notches and swing the retainer downward. This will release the bulb in the very center of the unit.

4. Pull the bulb out by it's base. It's about 3" long and comes straight out. Don't touch the glass if you intend to reuse the bulb.

5. The Toyota HID bulb is part # 90981-20024 (for my 2007 ES350).

6. Holding the new bulb by the base and without touching the glass, push the bulb back into the hole. There are notches & tabs in the base and mount that must match. Just rotate the bulb until it catches.

7. Reset the retaining spring by swinging it up and pushing it in while pinching the curled ends a bit. Release the ends when they lock into the metal notches on the housing. Make sure the retainer is secure before proceeding.

8. Reattach the metal socket fitting by pushing in at and turning clockwise 45 degrees from roughly a 10:00 to a 12:00 position.

9. Reattach the plastic cover by turning it clockwise.

That's all there is to it.