'00 headlight connector melted.

colmd · Jun 22nd, 2007, 09:43

Hi All,

I'm having a problem with one of the headlights in my '00 S40. The bulb went and when I was replacing it I noticed the common wire and the plastic around it on the connector was partially melted. The replacement bulb didn't work. I checked the fuse and it's fine.

I'll have a look later on today to see if the melted plastic was causing some kind of obstruction to the connector but in the meantime has anyone seen anything like this before? Where else should I be looking for problems?

Thanks,
Colm.

T4Viper · Jun 22nd, 2007, 10:38

If you have a volt meter confirm current is getting to the actual bulb holder....you can then establish if its the unit or wiring prior to...

leeleefocus · Jun 22nd, 2007, 11:09

there is a high probability that what you have there is a high resistance joint(resistance=heat especially when dealing with that amount of current that is running through those connectors) What this means is there is a bad connection which needs to be sorted or it will just carry on cooking until it fails(sounds like this has already happened) A poor contact can be caused by many different things but it is normally dirty contacts or not enough surface area on the contact points. Make sure all the contacts are clean and that they are nice and tight.

colmd · Jun 22nd, 2007, 11:19

Thanks for the quick replies.

I'll check the voltage at the connector and see that at least power is getting to it.

Assuming that this was caused by some obstruction on the connector I'll have to replace/refurb the melted connector before I can hope to solve the problem. The next questions is where do I look for a replacement connector? I'm sure the main dealer will want to replace the entire head lamp assembly.

I know I could just directly connect the spade connectors to the back of the bulb but that would just irritate me every time I saw it...

Colm.

T4Viper · Jun 22nd, 2007, 11:32

Quote:

Originally Posted by colmd

Thanks for the quick replies.

I know I could just directly connect the spade connectors to the back of the bulb but that would just irritate me every time I saw it...

Colm.

How often do you look at the rear of the bulbs mate ?

Connectors are a few pounds from a Volvo dealer - a friend replaced his not to long ago as broke it during replacment - workshop had a spare and only cost him £1....

colmd · Jun 22nd, 2007, 13:39

You're right it's not like I'd look at it every day but I'd know it was there....

Maybe when I try to buy the connector I'll ask my local Volvo dealer to sell me a book on how to stop being so fussy and just live with it

Colm.

colmd · Jun 26th, 2007, 23:43

The story continues...

I picked up a replacement connector, not quite the same style but it fits. However, the headlight still isn't working.

I measured the voltage on both full and dipped lights, it's just under 12v. It also switched as it should between off, on, dipped and full. Finally I tried two different bulbs, both the same type as the blown one I originally took out.

I can only conclude that there's insufficient current getting to the bulb to start it up. Does anyone have any suggestions on where I go from here? I don't have a Haynes manual so I've no idea what's before the 10A fuse in the box. Is there a relay somewhere to control both lights together?

Any other ideas before I give in and hand my car, and credit card, over to the main dealer?

Thanks,
Colm.

malb · Jun 27th, 2007, 07:28

Problem will be the earth lead from the bulb connector to chassis. This is what melted the connector body in the first place. Correct input voltages are present according to previous posts, but the earth path from lamp to chassis is high ressistance, blocking current.

Did you just replace connector housing, or connector and harness back to main wiring harness?

With a multimeter, measure the resistance from the bulb earth terminal contact in connector back to the battery negative terminal (bulb disconnected). This must be less than 0.1 ohm resistance as it carries at least 5 Amps when H/L is on.

If you only have a voltmeter, connect the bulb into circuit and measure voltage from bulb earth terminal to battery negative terminal with H/L on. Must be no more than .25v, but start test with meter on 12- 20 Volt range and step down ranges if reading indicates safe to do so.

colmd · Jun 27th, 2007, 16:00

I only replaced the connector.

It doesn't matter too much now but here's a picture of the burnt out connector:

http://importyourmotor.com/images/DSC00349.JPG

Where is the earth connection on the bulb connector? I presume it's somewhere around where the bulb fits into the back of the headlight assembly. Would there not be a common earth path for both the parking bulb and the dipped/full headlight? The parking bulb is working correctly.

Thanks,
Colm.

Jun 22nd, 2007, 09:43	#1
colmd Old before his time... Last Online: Oct 12th, 2011 23:31 Join Date: Sep 2006 Location: Athlone	'00 headlight connector melted. Hi All, I'm having a problem with one of the headlights in my '00 S40. The bulb went and when I was replacing it I noticed the common wire and the plastic around it on the connector was partially melted. The replacement bulb didn't work. I checked the fuse and it's fine. I'll have a look later on today to see if the melted plastic was causing some kind of obstruction to the connector but in the meantime has anyone seen anything like this before? Where else should I be looking for problems? Thanks, Colm.

Jun 22nd, 2007, 10:38	#2
T4Viper Member Last Online: Oct 12th, 2007 09:16 Join Date: Apr 2007 Location: London	If you have a volt meter confirm current is getting to the actual bulb holder....you can then establish if its the unit or wiring prior to... __________________ *Chuck doesn't sleep - he waits.....*

Jun 26th, 2007, 23:43	#7
colmd Old before his time... Last Online: Oct 12th, 2011 23:31 Join Date: Sep 2006 Location: Athlone	This light is officially a head wrecker... The story continues... I picked up a replacement connector, not quite the same style but it fits. However, the headlight still isn't working. I measured the voltage on both full and dipped lights, it's just under 12v. It also switched as it should between off, on, dipped and full. Finally I tried two different bulbs, both the same type as the blown one I originally took out. I can only conclude that there's insufficient current getting to the bulb to start it up. Does anyone have any suggestions on where I go from here? I don't have a Haynes manual so I've no idea what's before the 10A fuse in the box. Is there a relay somewhere to control both lights together? Any other ideas before I give in and hand my car, and credit card, over to the main dealer? Thanks, Colm.

Jun 27th, 2007, 07:28	#8
malb Member Last Online: Dec 29th, 2013 11:04 Join Date: Apr 2007 Location: Melbourne	Lamp earth lead Problem will be the earth lead from the bulb connector to chassis. This is what melted the connector body in the first place. Correct input voltages are present according to previous posts, but the earth path from lamp to chassis is high ressistance, blocking current. Did you just replace connector housing, or connector and harness back to main wiring harness? With a multimeter, measure the resistance from the bulb earth terminal contact in connector back to the battery negative terminal (bulb disconnected). This must be less than 0.1 ohm resistance as it carries at least 5 Amps when H/L is on. If you only have a voltmeter, connect the bulb into circuit and measure voltage from bulb earth terminal to battery negative terminal with H/L on. Must be no more than .25v, but start test with meter on 12- 20 Volt range and step down ranges if reading indicates safe to do so. __________________ Drive it till it drops... Then kick it back to life!!!

Jun 22nd, 2007, 11:09	#3
leeleefocus Member Last Online: Jul 14th, 2019 09:57 Join Date: May 2007 Location: bath	there is a high probability that what you have there is a high resistance joint(resistance=heat especially when dealing with that amount of current that is running through those connectors) What this means is there is a bad connection which needs to be sorted or it will just carry on cooking until it fails(sounds like this has already happened) A poor contact can be caused by many different things but it is normally dirty contacts or not enough surface area on the contact points. Make sure all the contacts are clean and that they are nice and tight.

Jun 22nd, 2007, 11:19	#4
colmd Old before his time... Last Online: Oct 12th, 2011 23:31 Join Date: Sep 2006 Location: Athlone	Thanks for the quick replies. I'll check the voltage at the connector and see that at least power is getting to it. Assuming that this was caused by some obstruction on the connector I'll have to replace/refurb the melted connector before I can hope to solve the problem. The next questions is where do I look for a replacement connector? I'm sure the main dealer will want to replace the entire head lamp assembly. I know I could just directly connect the spade connectors to the back of the bulb but that would just irritate me every time I saw it... Colm.

Jun 22nd, 2007, 13:39	#6
colmd Old before his time... Last Online: Oct 12th, 2011 23:31 Join Date: Sep 2006 Location: Athlone	You're right it's not like I'd look at it every day but I'd know it was there.... Maybe when I try to buy the connector I'll ask my local Volvo dealer to sell me a book on how to stop being so fussy and just live with it Colm.

Jun 27th, 2007, 16:00	#9
colmd Old before his time... Last Online: Oct 12th, 2011 23:31 Join Date: Sep 2006 Location: Athlone	I only replaced the connector. It doesn't matter too much now but here's a picture of the burnt out connector: http://importyourmotor.com/images/DSC00349.JPG Where is the earth connection on the bulb connector? I presume it's somewhere around where the bulb fits into the back of the headlight assembly. Would there not be a common earth path for both the parking bulb and the dipped/full headlight? The parking bulb is working correctly. Thanks, Colm.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)