I notice that one of my headlights shines at full intensity when I put sidelights on - i.e. headlights pop-up and one headlight is dim, the other is bright. Sidelights are OK.
Any ideas?
Rob
Does the bright one get any brighter on main-beam?
Have you tried a pair of new bulbs or are they old sealed-beam lamps?
Will check. Headlights work ok in that they dip/full Ok. Think I have sealed beams but will have a look.
Car was rather wet and I wonder if I have a short. If I pull out the relay (I think I read this was HD22) this I believe stops the headlamps popping up on sidelight setting and so my problem goes away but is there a downside to removing the relay?
Regards
Rob
You have a very bad earth, and you need to find it quick before the wire melts,take the headlight unit out and check the 3 pin spade connection block to the bulb has not gone furry,also check the earth block on the body in the engine bay under the wiper motor, held in place with a 10mm head bolt,undo it and give a good clean to make sure it as a good earth again.
Hi
I agree with your bad earth diagnosis, but how does that result in wires melting? The bad earth means high rsistance in the circuit, which means less current, which means less heat, ie no melted wires.
Alan
Dont mean to sound like I have bought the t-shirt but…I have seen a repaired this fault loads of times and it will melt the connection to your headlight bulb and wiring.
Choice is yours really if you do not want to take the advice,just trying to help the OP?
Alan wait until this happens to your Mk 2,because it will at some point,and the body earth points for the light units left and right are under you light units,so the units need to be removed to get access to them.
This is stuff I have forgot years ago on these roadsters,just to be big headed.
Regards
Okay, when it happens to my car I will report back. Just to mention that I am/was an electro/mechanical engineer with almost 50 years experience of testing and inspection of electrical installations both medium and low voltage and I have been fixing cars for more than 60 years and I’m just trying to understand the physics of the overheating.
Good for you Alan,you have your field and I have mine
,and I am sure that your personal knowledge is second to none and as served you well over the years and paid your morgage, but it is still a fact that this has happened (if this is the problem?)and will at some point to many of these mx/roadsters, maybe the heating occures because it’s trying to find an earthout through the lives? with one failing?
It’s mainly about 4>6 " of loom (but I have had a lot worse) and headlight bulb pulg/connection that needs cutting out and replacing, the plug melts down and falls apart, and I have found that this happens worse in the Mk 2’s
I don’t pretend to be the all seeing all knowing on why it melts, I just know the cause and how to but them right again, because that’s what I do, keep them on the road, and to be honest that is all I need to know, each to their own,and I am sure the OP does not need to get deep into the in’s and out’s on the electrics of a car,just on how to repair his fault,if this does not cure the problem then the next step is to go deeper?
As you have pointed out with experience, I have not been doing this for over 20 years now and not picked up something
In your wide knowledge of electrical systems, It’s over to you then on the subject.
Kind Regards
Basic electrics
If the contacts in the connector are dirty there will be increased
electrical resistance at that point. There will be a voltage drop
across the resistance which accounts for the dimming. The current
flowing through this resistance creates heat which further deteriorates
the connection. The process continues until the contacts are eventually
burned away.