[xsnrg]

http://www.toyotanation.com/forum/t81908.html

It continues... for example, I had a passenger side burnout a few weeks ago and lived with it but decided to replace the bulb with a brand new spare I had been carrying in the trunk. So I replace it in Charleston, SC before heading back to Durham, NC and by the time I hit Columbia, SC, the DRIVERS side bulb went out. Coincidence? Normally I'd be willing to accept the possibility, but this has happened before. Hard to believe that is a faulty socket...something else seems awry. No one else have this happen before?

Who can tell me what voltage I should find at the sockets? Any other tests I can do or things to look for?

 

[Cyorke]

When you ahve a bulb burn out you should do your best to replace it as soon as possible. There is the possibility that the one burnt out causes the voltage to be slightly higher going to the other which even for a short period of tiem can cause the bulb to burn out prematurely.

As for voltage at the light. if the car is not running the voltage should be right at 12v. which is battery voltage.

WIth it running it will be higher since it is running off of the alternator. I jsut wnet and checked my 94 camry and with the car running it was 14v+/-.5 on either the low beam or high beam.

 

[Mike Gerber]

You might want to check the output of the alternator. A defective internal regulator inside the alternator can cause overcharging and blow lightbulbs. Use a DVM like Chris did, but check at the battery terminals with the engine running. Have someone rev the engine a bit. You shouldn't get more than 14.7 volts at the battery. If you are getting noticeably more than this your alternator (actually the internal regulator) is defective and the alternator needs to be replaced or rebuilt.

Mike

 

[jhbhatia]

check this in this order:
1. alternator
2. battery

 

[Eye8Pussies]

also, check your harnesses...who knows what else may be going on?

I used to have bulbs burn out earlier than expected, and it was due to a loose harness where the socket meets the bulb and it would constantly shift (or something) and it led to prematurely dying bulbs as well as eventually a melted harness