I keep blowing fog light bulbs-why?
 

I have a 02 lariat screw. For some unexplained reason I keep blowing out the fog lamp bulb on the right side only. I have checked the lamp assembly and the connections over and over again and can't seem to find the problem. My lens is not cracked, or broken in any way. The connection is tight as well. Any help or suggestions would be appreciated!!!

Are you toucing any part of the bulb with your bare hands?

Is the glass on the bulb cracking or breaking or going black or is the filament just breaking?

What bulb are you using? And how often have the previous bulbs lasted?

No I do not touch the glass of the bulb while installing the bulb. I use 9145's thats what the owners manual said the bulb number was. It is a Slyvainia PN. Are Slyvania bulbs crap? When I replaced it again this morning for the 3rd time since fri I put some di electric compound in the receptcale for the wiring harness on the bulb. When the bulb blows the glass is completly gone from around the fillament.I purchased the first bulb at wally world and then when it blew i took it back and exchanged it for another bulb. Driving home from my family reunion last night it blew out again. I took it out this morning and went to Advance auto and got another bulb. This time I added the di-electric to the socket on the bulb. I am hoping that this one lasts for a while!!

Sounds like a short. DC voltage is supply/demand. If there is a short in the connector it will surge to either a fuse rating or your bulb. It will also follow the path of least resistance. Usually means the short is in the connector or bulb socket if the fuse didn't blow.

Yup I would check those wires

The glass capsule is blowing apart ?

Are you getting all the bulbs from the same place ?

A short in the wiring ( regardless of where ) to ground is not going to blow a bulb apart, it will blow the fuse.
It was said above, shortest path, and a short to ground in the wiring or in the bulb connector is a short to ground, it will take the fuse not the bulb.

I am taking a SWAG if you are getting them from the same place, it was a bad run of bulbs that are having an issue with the manufacturing, causing the capsule to blow apart, considering you are cleaning the bulb with a clean paper towel and not touching the glass at install ( you are sure you are not rubbing up against something or using a dirty rag ).

If it was an issue with your electrical system, you would have more problems than just the one bulb ( considering both fog lamps are on the same circuit ),

Try a different Sylvania bulb from a different location. You can go to the point of getting a XV instead of a ST bulb, but I do not think the same run would have made it to both Wally World and Autozone. It is a possible but not probable

The breaking glass leads me to believe excessive heat generation, either by touching the glass or something else. I'm betting it was the first of the two.

Hello All,

I have recently just started having the same thing happen to my 2007. To answer a few of the questions that were asked above:

No, I did not touch the bulb during installation. I held it by the connector end the whole time.

Yes I have purchased bulbs from 3 different places. Auto Zone, Pep Boys and an online retailer. Same results every time. Started happening no more that 6 months ago, but I have already replaced the same bulb three times.

Yes, the last two bulbs broke the glass when they went.

In another post on this forum, some else had the same issue in 2007 with their 2004. He was told to check for improper installation (a.k.a. a lose bulb), the housing itself vibrating causing the bulb to pop. And lastly, as someone here mentioned excessive heat build up. That being said, I noticed sometime last year, that my fog light lenses appear to have gotten distorted from what looks like heat right in front of where the bulb comes through the housing. This is on both driver and passenger sides, but only the passenger side keeps breaking. I have also discovered what appears to be small water droplets inside the housing on the passenger side. I cannot be 100% sure that it's not just more distortion or actual moisture. Again, I read some place that moisture will cause this to happen in an enclosed area with the bulb generating so much heat.

Before I spend another dime on bulbs or housings, I wanted to see if anyone had a suggestion. Or is there anyone out there that makes an aftermarket direct replacement for the round 2" - 3" fog light, you know, something less prone to this problem.

Any thoughts or suggestions is greatly appreciated.
Thanks in advance.

Considering there are 3 cases, kind of hard to qualify prone to this problem, as 3 cases ( or 100 ) is not prone to happen with the number of them in use. There are at least 100 members running 65W 9005 bulbs in the housing without this issue.

If you have heat distortion in both lenses, what bulb are you installing ?
- That is not going to happen with a 9140 or 9145 bulb in the factory housing.

How are you cleaning it before installing it ?
- You only make mention of holding it by the connector, nothing about cleaning it.

Have you checked the fog lamp housing to see if it is loose ?

I'd pull the whole thing off and check for abnormal water buildup. But 90% of the time breaking fog lamps and/or bulbs is because of thermal shock of the glass.

I don't specifically clean/wipe the bulb before installation. I take it right from the pakage, by the connector, install it into the housing and then make the connection.

The last bulb I installed 7 days ago was broken by yesterday in the housing. The housing did not feel loose, but I will double check that to be 100% sure. There has been no rain or snow in the last week, so environmental conditions have not contributed to it (i.e. driving through puddles or snow build up in the wheel well). It is cold, so the change in temp from being off and outside all night to on and heating up might be causing moisture in the housing.

Typically, I have boght Sylvania's as replacements. I don't recall the exact number, but I know most of the auto parts stores near me don't carry the catalog number replacement, but they have a suitable match. I'm sure it's one of the numbers listed by sscully.

I said prone simply because now that mine is acting up I notice others on the road with the same bulb cooked and what I have seen on-line so far. It appears to be a common problem that I have just taken notice of.

I have found some direct replacement projector halogen fog lights that fit my style bumper, but as I said I didn't want to spend more money if I'm just going to burn out another light. You can see them at fordf150foglights dot com. I found the same ones somewhere else for $170 so these are a little less.

Don't get me wrong I wasn't mad when I said I didn't want to spend another dime, It's just frustrating when you replace a bulb that has worked for years and now it only lasts days if you're lucky.

I can put a meter to the connection and check voltage, Ohm's etc. but I would think that a bad ground or some other wiring issue would either blow the fuse, as it should be designed to do, or have some effect on the drivers side light at some point. I don't have a wiring schematic for my truck, so maybe I'm just talking out of my tail pipe.

Thanks again guys.

Oh yeah, I'll try to get a photo of the lenses posted so you can see the heat distortion I was talking about.

Now by "broken" you mean the filament, correct?

Which bulb are you using?

Post pics of the housing and bulb if possible.

Filament is broke by default, by the time I see it's out, the glass has broken too. I can see from the outside pieces of glass from the bulb in the bottom of the lens/housing.