Bulb holder.......

[lee.gardiner]

Hi. New today to the forum. I hope someone can help with an issue I have with a passenger side dipped headlight issue.
18 months ago a bulb failed on my golf and when I took it to Halfords for a replacement bulb the guy told me that the bulb holder had burnt out/melted and needed replacing.
I took the car to my local independent garage and was told that the holders were hard to source and that a replacement headlight was needed , around £130 quid as I remember.
It worked for a time but failed and on examination the holder had melted again although pushing the bulb in a bit made it work , and this has been ongoing now for months with repeated visits to halfords to have this done (I can't get my hand into the space to twist it into place) It was noted that the rubber cover was missing too if this helps identify a possible issue.
The bulb appears to be fine and isn't blowing , but the bulb holder IS melting and I refuse to install yet another headlight unit!
I have seen some holders on eBay which look ok but aren't cheap however , I'd prefer to find out what's causing the melting before I start spending more money on the holders.
Is this a common fault and can anybody offer some advice please?

 

[golfdave]

Do you have xenon's or halogens??

If the rubber covers have been missing then water gets in & could cause the wires/contacts to short out.....heat damage/melting is usually caused by a wire which is shorting...also bad corroded contacts or a bulb that draws too much power.....

Have you had any blown fuses or warning lights o the dash?

 

[DV52]

@lee.gardiner: Can't be any mystery about "what's causing the melting". It has to the result of what's called "I^2R" losses which is a fancy way of saying "the heat generated by a large quantity of electrical current passing through a high resistance joint. The dipped-beam lamp is a high current device.

Given that the bulb holder is a simple device, my money is on the quality of the mating connectors. There are 2 x possibilities IMO:

1. If the mating plug to the lamp bulb is not sufficiently strong in pinching each side of the copper plug against the pin on the bulb - a high resistance joint will result and the "R" in the formula becomes large which generates heat
2. If the absence of the rubber plug has allowed water and/or detritus to accumulate in the bulb holder, the mating contacts could become "rusted", or pitted. Again, this causes high "R" in the formula and high heat

If this was my car, I would closely examine the pins on the lamp and the metal parts of the mating socket (including the wire-loom terminations) for signs of abuse, looseness and/or pitting

Don

 

[lee.gardiner]

Do you have xenon's or halogens??

If the rubber covers have been missing then water gets in & could cause the wires/contacts to short out.....heat damage/melting is usually caused by a wire which is shorting...also bad corroded contacts or a bulb that draws too much power.....

Have you had any blown fuses or warning lights o the dash?

Sorry for the late reply! Rubber cover missing on the dipped headlight aperture only (the problem one) The warning lights just tell me to "check nearside dipped headlight" That's the only message I've ever had. Thanks for replying

 

[lee.gardiner]

@lee.gardiner: Can't be any mystery about "what's causing the melting". It has to the result of what's called "I^2R" losses which is a fancy way of saying "the heat generated by a large quantity of electrical current passing through a high resistance joint. The dipped-beam lamp is a high current device.

Given that the bulb holder is a simple device, my money is on the quality of the mating connectors. There are 2 x possibilities IMO:

1. If the mating plug to the lamp bulb is not sufficiently strong in pinching each side of the copper plug against the pin on the bulb - a high resistance joint will result and the "R" in the formula becomes large which generates heat
2. If the absence of the rubber plug has allowed water and/or detritus to accumulate in the bulb holder, the mating contacts could become "rusted", or pitted. Again, this causes high "R" in the formula and high heat

If this was my car, I would closely examine the pins on the lamp and the metal parts of the mating socket (including the wire-loom terminations) for signs of abuse, looseness and/or pitting

Don

Thank you Don. I'll give this info to the the garage and get them to do a full investigation on it with this in mind. Considering it's a brand new headlight unit it's pretty disappointing!

 

[lee.gardiner]

Sorry for the late reply! Rubber cover missing on the dipped headlight aperture only (the problem one) The warning lights just tell me to "check nearside dipped headlight" That's the only message I've ever had. Thanks for replying

Oh! And they're standard bulbs , Halogens