# Headlight bulb wiring harness melted. known problem?



## Gtiminar (Jan 6, 2009)

i have a 04 gti 1.8t mk4. 
My passanger headlight keeps going out but the filiment is fine. 
I do not touch the bulb either during install. 
I noticed that the female wiring harness that plugs into the h7 bulb was partially melted. 
I think that its getting to hot and frying out the bulb components and caused part of the harness to melt. 
When i put in a new bulb it works fine. 
I used OEM bulbs and Osram nightbreakers 55watt H7's 
I have no problems with the driver side light. 
I called the VW dealer and parts guy didnt want to give me advice on what the problem is or how to fix it. (figuers) 
I am going to order a new wire and harness and replace it but wanted to know if this is a common problem and if there is a reason why the harness got partially melted. 
Any info would be helpfull. 
I searched for similar problems but didnt find anything. Im still getting use to the new format for the forum so maybe i just couldnt find it. 
Thanks


----------



## dennisgli (May 17, 2003)

That's a common problem with Jettas but I've never heard of it on a Golf - they use different bulbs.


----------



## Gtiminar (Jan 6, 2009)

thanks for the reply. 
What caused it? How do i go about fixing it? If i just replace the wire and harness will it happen again? Is there a way to fix it besides just replacing the wire and harrness. 
I keep putting new bulbs in somthing is causing it to over heat and now it melted the harness. 
The dealer doesnt want to tell me anything about it unless i pay $80 hr to have them fix it just like they wont tell me why the courtesey light on my drivers side door is broke because the locking module is broke. 

never again VW


----------



## fixmy59bug (Apr 9, 2002)

Oh for Petes sake, man. Come on.

You're getting all worked up over common sense.

First, the service dept can not tell you what is up with your headlights without a diagnosis. Time is money, and noone works for free. The service dept does not know what kind of bulbs were put in the headlights. How many times do you think aftermarket parts were used in a car and the customer tries to get it fixed under warranty ("Duh, I dunno wha happened").

Second, The parts guy can not tell you what is going on because they are not trained technicians. Most of them don't know how to work on cars. The customer or technician tells them what part they need, and the parts guy gets it for them. For liability reasons, us parts guys CAN NOT give out information on repairing your vehicle. If we give you wrong advice, or you hear us wrong and fry something, the dealership doesn't want to be held liable.

What caused it? Heat. Bulbs work by converting electricity to light. a major byproduct of said conversion is heat. When plastic heats up, it turns black and melts. Electrical wires carry said electricity to the bulb and if the wire is too small or fragile, it heats up which can lead to melted harnesses. If there is corrosion on the electrical connectors, the wires can heat up and melt. If there is a bad ground, the wires can heat up and melt. If the wattage of the bulb is higher than the maximum amount of amperage that the wires can handle, the wires can heat up and melt.

See where I am going with this?

As far as fixing it, there are a couple of different options depending on the cause.

Cut and splice new wires, replace the whole headlight harness, replace the whole headlight assembly.

If higher wattage bulbs were used, Don't do it again.

No need to get so worked up when common sense is applied to a common problem. This is not just a Vw thing. It's the law of Thermodynamics.


----------



## Gtiminar (Jan 6, 2009)

all of what you just said "Electrical wires carry said electricity to the bulb and if the wire is too small or fragile, it heats up which can lead to melted harnesses. If there is corrosion on the electrical connectors, the wires can heat up and melt. If there is a bad ground, the wires can heat up and melt. If the wattage of the bulb is higher than the maximum amount of amperage that the wires can handle, the wires can heat up and melt".
None of the above. no corrosion, (stock oem bulb), stock wiring and harrness. 

You cant just buy the plug harrness. Dealer only sells the enitire headlight harrness $250. + 2hrs labor.
So I bought a H7 Harrness plug from local parts store, cut and soderd but it sticks out to far and i cant put the back of the headlight cover on. I took the wires out of the harness and pluged them directly into the bulb. They are on secure enough so that they wont touch or come off. 
problem solved and fixed. 
I wouldnt be asking about this if this was a common sense issue. 
The dealer parts counter boy knew exactly what i was talking about and knew right away i couldnt order just the plug harness. His advice was to replace the whole harrness or pay VW $400-$500 to fix it.
Next time you tell somone to use common sense dont even bother replying to a post. All of what you had to say was useless info. 
The point of this post was to find out if this was a commone issue or problem with just my car.
Im trying to prevent it from happening again, rather then just replacing it and happening again.
All VW dealers are know for terrible customer service and they overcharge for bad mechanical service to. I have all the proof i need to say that. At least where i live everyone in town, dealers, used and new, mechanics, and body shops know how bad VW customer service is. Thats why we dont take our cars there for service.
Have fun working in a place that your known to be a ..... before we walk in the door
as i say and most aggree that have owned VW in the past.. Never again will i buy a VW. Service and problem sums it all.


----------



## dennisgli (May 17, 2003)

You asked if this was a common problem - I gave you an answer.

A bad connection between the connector and the bulb can cause overheating. You replaced both - that's common sense.

The dealer offered to sell you the parts that they would use to fix the problem. Not sure why you expected them to do more.

Sorry - stop whining.


----------



## Gtiminar (Jan 6, 2009)

whining? shhh. enough of you. you are just mad i called out the stealership cause you work there. 
they know the problem to most issues. just like the locking door module. rather then tell ppl the problem they say Oh you have to have a diagonstic $80 to see whats wrong then were gona charge you $100an hr. x 2 and you have to pay for the part. instead they should say yes its a common problem that the door module needs to be soderd or replaced. here is the part # shall i order one for you? 
another example is the ignition coil. " i never heard of that problem you better make and appointment for service to have them see whats wrong" all they had to say was yes you need to replace and get the current coils thats why engine is running rough. I will call you when the coil come in.
better yet just tell the customer that there is a major recall going on with ignition coils and VW will fix and replace for free. 
My Hondas never had any issues with headlights, locking modules, brake light switch, bearings at 70,000, the list of problems goes on and on and on with VW's. You never have to replace an igintion coil on a Honda. Never again will i buy a VW because of the dealer and service dept. and ppl like you that work there. Not to mention all the problems that a VW's have. Come on now... TDI? 5 cylinders? thats where VW is going with cars in the future?. Sigh 
and my buddies brand new 2.0 GTI he has to put a quart of oil in every 2 weeks or the car wont start? the turbo evaperates it? lol only a VW


----------



## fixmy59bug (Apr 9, 2002)

GTI, 

I'm going to try to be civil about this. Even though you may not like my answer.

While it may be true or not that us parts guys have all the answers, As I said above, We are not trained technicians. Most dealership managers do NOT allow their parts consultants to diagnose a car. And to say "Your car is running bad because the coils are faulty" is a diagnosis. I have been reprimanded once before for attempting to diagnose a customers car while not being a factory certified trained techncian.

What would you do if your car was misfiring and you came into my parts dept and I said (without having a proper diagnosis) "Your car is running bad because the coils are shot". So you spend $150 on new coils (Not an accurate price, just an example) and it doesn't fix the problem. Turns out, your engine harness has deteriorated and needs to be replaced to the tune of $375 (again, not an accurate price). Now, because the coils have been installed, they can not be returned. So you are stuck with some coils that were not defective, plus you have to spend another $375. How pissed would you be at me?

You have to try to understand that while we may know the common issues with your specific generation of vehicle, we can not run the risk of misdiagnosing a car.

And if you think Hondas are not problematic, Think again. Vw's are not the only turbo cars to eat oil. Heck even the non turbo RX7's and RX8's eat oil.

And what, in your opinion, is wrong with the TDI's?


----------



## vortexnewbie (Jan 24, 2010)

fixmy59bug said:


> Oh for Petes sake, man. Come on.
> 
> You're getting all worked up over common sense.
> 
> ...


 you mean thermal harmonics :laugh:


----------



## Gtiminar (Jan 6, 2009)

TDI? $3.50 a gallon of diesal and they are slow like a semi. Gota love that smell to!! Oh i forgot they get 36MPG in the city and 40 highway oh wow spending $50 to fill you tank really pays for that!!!
NO one can work on them you have to take them to the dreded dealer for everything.

out of the 4 Hondas that we had in our family we never had any problems what so ever compared to the problems that we had with 2 VW's in my family. the list of problems with VW's goes on and on. From interior to exterior to engine to suspension.

Basically what im saying is that all the problems that i had with VW's I never had that problem with the Honda. Most of the parts are all the same to just different maker. 
I think that the biggerst problem with American VW's is that they are made in Mexico and Brazil. While the Hondas are made right here in my home state of Ohio. 
We have put so much money in maintance in the VW's and the problems just keep coming and coming.
My 94 Accord EX v6 180,000 miles, still gets 32 MPG. all i did to it was replace the ball joints and 1 wheal bearing and the rocker panel gaskets, muffler and center pipe. non synthetic oil and no premium fuel. Cheap 85 or 87octane $2.50 a gallon

my 04 GTI only has 80,000 miles on it i did timing belt $1000 just for that, coils, ball joints, tie rods, interior radio antenia the whole headliner had to come apart, locking door module, rear shocks, both headlights ball and socket broke, headlight harness, 2 front wheal bearings, gas cap, dashboard lighting, sunroof motor, ac condenser, mass air sensor, o2 sensor, licence plate lights (2 times), so much electrical work, center exhaust hanger, all the stupid little sqeaks and rattles and noises, the list goes on and on. Never will i buy a VW again. German Engineering??? Made in Mexico!!!!
Not to mention that the VW stealership have the worst customer service parts and service, they techs are not carefull and do clumsy careless work ( i have all the pictues and proof to show it) they cant even install rear brakes properly!!! drove down the road and the ebrake locked up! 
Im not even including all the sythetic oil and normal wear and tear.
the 94 accord V6 is so fast that is smokes my 1.8t GTI not even a challenge. 
VW= not worth the expence and the hassel of the dealer and the parts counterman


----------



## zooyorkpork (Oct 30, 2009)

what was the part number on the harness. and i think i have the same problem as you. http://forums.vwvortex.com/showthread.php?4992370-bulbs-burn-out-instantly


----------



## brus6286 (Jun 27, 2007)

oh boy.... really?

I went to NAPA asked for a replacement Headlight harness for my 01 jetta after i kept blowing out bulbs and eventually found the BURNT connector, NAPA had a "Universal" one for like $8 or something like that, cut, splice, solder whatever you want to do for connection repairs. TAPE or SHRINK TUBE and DO NOT forget the THERMAL ELECTRICAL GREASE.


----------



## fixmy59bug (Apr 9, 2002)

Gtiminar said:


> $3.50 a gallon of diesal


Wrong. Diesel is typically less than your premium gas. Currently in my area Diesel is about $3.09 per gallon while premium gas is approx $3.29.



> they are slow like a semi.


Wrong again. While stock TDI's may not be blazingly fast, They do accelerate rather quickly. Certainly quicker than a stock civic or other econobox. 



> Gota love that smell to!!


Well, You're right here. The smell of diesel is rather intoxicating. Certainly better than the smell of it's hydrocarbon cousin. Secondly, the newer clean diesel engines do not emit ANY smoke or smell. That's why it is called Clean Diesel.



> Oh i forgot they get 36MPG in the city and 40 highway oh wow spending $50 to fill you tank really pays for that!!!


And you're back onto the wrong track.The older diesels (for example, the MkIV's) were capable of getting 50 - 60 miles per gallon depending on how it was driven. Chipping the ECU actually GAINED fuel economy. 800 - 900 miles per tank is not unheard of. As a matter of fact, when I went to vegas for Wuste, I averaged 48 miles per gallon on the way out and 43 on the way back. I have never had to spend $50 to fill the tank. Get your "facts" straight.



> NO one can work on them you have to take them to the dreded dealer for everything.


Wrong. There are plenty of TDI specialists around the country. You just have to do a little bit of research.



> out of the 4 Hondas that we had in our family we never had any problems what so ever compared to the problems that we had with 2 VW's in my family. the list of problems with VW's goes on and on. From interior to exterior to engine to suspension.
> 
> Basically what im saying is that all the problems that i had with VW's I never had that problem with the Honda. Most of the parts are all the same to just different maker.
> I think that the biggerst problem with American VW's is that they are made in Mexico and Brazil. While the Hondas are made right here in my home state of Ohio.
> ...


Have you ever considered thatmaybe you don't treat your cars very good? I will BET that your cars are clapped out, raced, beat, put away with the turbo glowing, and generally neglected.

Your car hates you and I don't blame it.


----------



## RRSB_1971 (Dec 8, 2009)

You could also do what I am doing tonight.

In the past, I have had a headlight switch get melted on a Mk I Jetta I used to own. (Took it apart and scrap the switch until I got decent connectivity through it.)

On my Mk II & Mk III Jetta's I am adding a heavy duty headlight wiring harness from LMC Trucks to them. They are rated at 100/90W (high/Low). The part #47-3661 is what I order for my Jetta's. This is for single bulb headlights only. It is listed for 90 ford ranger(go by Part Number). Plus this one is only $30. They're are others out there I'm sure. This one has 2 relays High/low beams - 30amp










They have many more style available. You would need to figure out which truck is similar to your car. I used Autozone to figure out which truck would have the same headlights I had. It took me 3 attempts. if I had to do this on a Mk IV Jetta (I see you have a GTI) I would start with a search at newer Ford Ranger or 2000's model S-10's to see which had similar headlights bulbs as mine. If I couldn't get exact match I would get the one that is close & then go to Junk Yard & cut me some ends from a car similar to mine & then splice into one of LMC Kits.

Basically the factory runs the battery power through the headlight switch then to the lights. Marginally at best. 

This wiring harness plugs into 1 of the factory headlight wire. Then it just uses the headlight switch to energize the relays to allow battery power to go from battery to relays to headlights. 

Plus this helps when you have any issue with one side of the cars wire harness. I am doing it to help my headlight switches last a little longer.


----------

