Headlight problem

[rustic]

I'll earth the other headlight and get my mate to come down to take the voltages after lunch.

The bulb gets really hot (much hotter than the passnger side bulb) when both filaments are glowing.

With or without engine running, on dip or on main beam, the drivers headlight is dim with both filaments glowing, whilst the passenger headlight is approx 30% brighter and works correctly with each filament lighting individually and not together.

Cheers for your help Rustic :thumbs

It does sound like the earth on the other side, as this will cause some current to flow through one filament, then the other which means that the other filament on the other side will also glow, which you won't see, but will add heat to that bulb..

by the way which side have you earthed already?

best regards, Rustic.

 

[coco777]

It does sound like the earth on the other side, as this will cause some current to flow through one filament, then the other which means that the other filament on the other side will also glow, which you won't see, but will add heat to that bulb..

by the way which side have you earthed already?

best regards, Rustic.

I earthed the drivers side, the side with the problem.

 

[vince]

the problem im having is that when the sidelights are on the main beam is on very low, its only noticable as i wired in my spots so they now come on with the side lights, this is due to a bad earth on the sidelight circuit so i checked everything through and could find no problems, until io removed the taillight fuse. eureka! so its either shorting at the rear cluster or due to the towbar wiring, i havent checked through yet but im expecting some stripped cable.

 

[rustic]

the problem im having is that when the sidelights are on the main beam is on very low, its only noticable as i wired in my spots so they now come on with the side lights, this is due to a bad earth on the sidelight circuit so i checked everything through and could find no problems, until io removed the taillight fuse. eureka! so its either shorting at the rear cluster or due to the towbar wiring, i havent checked through yet but im expecting some stripped cable.

Read my earlier thread regarding my headlights are on dim when the side lights are on, and ignition on.
Some Mavs are wired this way.

Also check where you are feeding the wire for the spot lights from, I hope you are using a relay and suitable wire and fuses.
The wiring of the headilghts on my Mav put the bulbs in seies when on side lights, and if you choose the wrong wire then you could get problems.

 

[Terranical]

Read my earlier thread regarding my headlights are on dim when the side lights are on, and ignition on.
Some Mavs are wired this way.

Also check where you are feeding the wire for the spot lights from, I hope you are using a relay and suitable wire and fuses.
The wiring of the headilghts on my Mav put the bulbs in seies when on side lights, and if you choose the wrong wire then you could get problems.

What that man said - my Terrano is also a '94, it has what were called at the time dim/dip lights. The idea behind these was to prevent people driving on sidelights only, so when sidelights and ignition are on, the headllights also come on, albeit in a low power mode. This was introduced by the government at the time to cut down on accidents caused by people driving on sidelights only in poor light conditions i.e. fog, heavy rain and snow.
The car manufacturers immediately complained that this increased production costs without any proof that there was any advantage to be gained, plus governments of other car-producing countries refused to follow suit, so the whole thing was dropped very quickly.
The dim/dip feature works only on the dip side of the headlights, not the main beam, so IMO if you have voltage going to the main beam side when the dim/dip is active (when the sidelights/ignition are on) your problem is unlikely to be a poor earth connection, methinks a visit to an auto-electrician is needed - with a car 19 years old who knows what bodges have meted out to it by previous ham-fisted owners!

 

[vince]

there isnt enough voltage going through to light the low beam properly and the fact its earthing through the rear lights suggests that its a fault there as opposed to the front. dont worry my spots are wired in correctly with suitable multistrand cable and inline fuses:clap,

 

[terranobreakershropshire]

with regards melted plugs. i have had 3 or 4 breakers with this. always drivers side on them. 1 had high power bulbs the others didnt. i have wondered for a while what causes this. first thing i looked at was the bulbs.

 

[glanrichbex]

there isnt enough voltage going through to light the low beam properly and the fact its earthing through the rear lights suggests that its a fault there as opposed to the front. dont worry my spots are wired in correctly with suitable multistrand cable and inline fuses:clap,

Voltage doesn't go through anything - voltage is only a potential.

A hand held torch battery could be a small lead acid 12volt 1.3Ah.

The fact it is this 12volt battery will not start your truck because it has very little CURRENT ( 1.3 Amps per hour or 1 ampo for 1.3 hours ) behind it.

If the load ( in this case a filament ) pulls more current than is available to it, then the voltage across the load gets pulled down.

500,000volts at 20 milliamps will not kill you.

 

[vince]

Voltage doesn't go through anything - voltage is only a potential.

A hand held torch battery could be a small lead acid 12volt 1.3Ah.

The fact it is this 12volt battery will not start your truck because it has very little CURRENT ( 1.3 Amps per hour or 1 ampo for 1.3 hours ) behind it.

If the load ( in this case a filament ) pulls more current than is available to it, then the voltage across the load gets pulled down.

500,000volts at 20 milliamps will not kill you.

give that man a doughnut:clap, sorry my bad.there isnt enough current going through it to make it obviously lit up, so i cant see why it would be this way from the factory????

 

[danielj]

with regards melted plugs. i have had 3 or 4 breakers with this. always drivers side on them. 1 had high power bulbs the others didnt. i have wondered for a while what causes this. first thing i looked at was the bulbs.

Can you recall if the plastic covering the wires at the plug were split or a bit disintigrated. I'm wondering could it be poor quality wires and the insulation breaking up over time and allowing wires to touch. Wires on mine had been exposed for some time as they were almost corroded through in places just before the plug. Could be something going in the plug itself but mine was so melted you couldn't tell anything from it.

 

[terranobreakershropshire]

tbh they were in a right mess so it made it hard to tell. the plastic bulb fitting with the 3 spades in is always melted along with the 3 wires. i can see why they have gone on fire with people. they all looked like the fuse should have blown before they got so bad.

 

[vince]

mine were both melted, the o/s- sorry right hand side was conciderably worse and had melted right through so was in 2 parts. i removed them and replaced them with some spare motorbike ones i had. the bike ones have a rubber waterproof cover on them so i reckon they will be better suited to the offroad nature of the car.

 

[glanrichbex]

give that man a doughnut:clap, sorry my bad.there isnt enough current going through it to make it obviously lit up, so i cant see why it would be this way from the factory????

It wasn't that way when it was manufactured,

They don't use the best material in car wiring and furthermore the diameter of the wires is to minimum spec to keep the cost down, The problems begin after years of running currents through wires to the maximum ( or even exceeding the rating ). The outside of the strands of the wires oxidise with the heat generated and as D.C travels on the outside of the cable ( skin effect ) the cable increses resistance by a few ohms. This is certainly enough to reduce the current flow, but the crimped connector at the end of the wire will fail in time due to the oxidisation of the surface of the wire and produce a hot spot where the crimp will heat up.

 

[stinka]

I fitted cheap 100/90 bulbs to mine the other month

So far so good, with a few 3 hr + journeys at night and no fires yet

 

[glanrichbex]

I fitted cheap 100/90 bulbs to mine the other month

So far so good, with a few 3 hr + journeys at night and no fires yet

You are stressing your wiring, it will be overheating the wiring and it could be just a matter of time.

As I said this is a progressive time issue - just hope the wiring eventually burns out somewhere you can get to it and not in a loom of other cables

If you want to uprate your headlamps, use a relay and create a new fused circuit from the battery.

 

[glanrichbex]

Most vehicle fires are caused by small electrical faults. Wires burning out and melting their insulation. The bare hot wire then melts into the insulation of neighbouring cables in looms like cheese wire. Some of these cables could be involved in higher current rated circuits.
Even if your truck doesn't catch fire, you will have one hell of a job to sort it all out.

 

[Terranical]

I fitted cheap 100/90 bulbs to mine the other month

So far so good, with a few 3 hr + journeys at night and no fires yet

I tried some 100/90w bulbs in my T2 not long after I got it, didn't find much improvement over the originals. Then I tried Osram Nightbreakers, no going back after that, they are such an improvement.

 

[rustic]

as D.C travels on the outside of the cable ( skin effect ) the cable increses resistance by a few ohms. This is certainly enough to reduce the current flow, but the crimped connector at the end of the wire will fail in time due to the oxidisation of the surface of the wire and produce a hot spot where the crimp will heat up.

Sorry old chap, I have to correct you on Skin effect, this applies only to alternating current, not DC.
ie it is a particular issue on high frequency transmission, and can also be seen at audio frequencies, and multi strand cables are better than soild copper in these applications.

I agree with the hot spot issue, as the cable oxidises and a voltage drop will occur.

bet regards, Rustic

 

[glanrichbex]

Sorry old chap, I have to correct you on Skin effect, this applies only to alternating current, not DC.
ie it is a particular issue on high frequency transmission, and can also be seen at audio frequencies, and multi strand cables are better than soild copper in these applications.

I agree with the hot spot issue, as the cable oxidises and a voltage drop will occur.

bet regards, Rustic

It's to do with A.C theory which I forgot everything after leaving college 20years ago :nenau
I thought D.C current flowed on the outside of a conductor but it doesn't.

Problem is nowadays we've become a nation of board changers and the old grey matter is failing :doh

 

[vince]

I fitted cheap 100/90 bulbs to mine the other month

So far so good, with a few 3 hr + journeys at night and no fires yet

didnt it blow your fuse when on flash? i use these in my bike but only on dip and main as it draws too much current if i flash and blows my fuse.