headlight bulbs burning out too quickly

[lr3seowner]

I apologize if this topic has been discussed previously, but I couldn't find a solution in my online searches. My headlight bulbs have been burning out too quickly - after 2-3 months approximately. I have checked the wiring and fuse box but nothing looks off. I'm wondering if anyone has dealt with this problem before and how they were able to fix it?

Thanks.

 

[Globetrotter]

Assuming you do not use cheap globes then it is possible that the alternator regulator is not working properly, putting out too much voltage.

 

[bbyer]

What kind of headlights to you have - the small round lens type with the Xenon HID bulbs within or the larger type with the internal reflector and halogen bulbs?

The problem I had was rear tail lights or the brake light bulbs burning out more often than I thought they should - perhaps every six months or so - not all of them all at the same time - just continually it seemed replacing rear bulbs. My HIDs were OK, but if you have the halogen bulbs, there are not much different than a conventional tungsten bulb - just the gas.

At some point I decided my alternator was not working properly, (not due to the bulb problem), but more because the alternator voltage never varied. ( I have a ScanGauge voltage readout device mounted on the dash.)

Bottom line was I eventually replaced the alternator and now it is rare I have to change tail/brake light bulbs.

I believe the regulator within the alternator was defective. There is apparently a fail safe voltage ~13.3 VDC that the regulator defaults to that allows the alternator to continue to generate amps sufficient to charge and generally run the 3 for months on end. While all seems well, it is not true.

In other words, you may have a defective regulator located within the alternator that is masking a problem.

Within the link below, there are a number of files related to the alternator, regulator, and the electrical system generally.

https://www.disco3.co.uk/gallery/thumbnails.php?album=3801

 

[lr3seowner]

Thanks for the input. I’m worried it may be the alternator starting to fail. This helps to further validate that inclination.

 

[Globetrotter]

If you are mechanically minded and good with a soldering iron, you can repair the alternator with a diode pack

 

[bbyer]

When I had an alternator problem, I could not even get it apart - the main screws just would not undo. I guess it does not take much for me to give up, but in my case, I presumed the trouble was the internal regulator as the alternator still seemed to make lots of amps; there just seemed to be a voltage problem.

The rebuilt I purchased lasted about a week - same sort of voltage problem, lots of amps, fixed volts. The replacement lasted about five years, and the main belt, a couple of hours - the replacement alternator came with a wrong groove pulley that I did not notice.

I swapped pulleys and then the charge voltage etc fluctuated as it should from about 13.5 on hot days to 15.1 on real cold days at just after startup. The normal operating voltage is about 14.3 volts as displayed on my ScanGauge II plugged into the OBD port.

Regardless, count the number of grooves in the replacement alternator before you install - you get less practice but it is easier that way.