General Land Rover TD5 2004 - Instrument Illumination!

[Lancelot]

Hullo!

Does anyone have an idea why Fuse18 blows so frequently, (instrument panel illumination and side light)? Yesterday it blew as soon as I turned the heater on heading down a mountainside in Turkey in the rain - at least it was not the wipers!

 

[Geobloke]

It sounds like one or more of your earths need cleaning or part of the loom is shorting through abrasion. Common places are where the loom bends around the engine block. Search for rubbing on the loom insulation.

 

[andy63]

Don't know you vehicle but a quick look at the wiring diag's available on landrover workshops site does show the heater blower and sidelights share a common earth point.. (K108. 0550)
Fuse 18 serves the sidelights so you have a short somewhere on that circuit..

 

[Lancelot]

It sounds like one or more of your earths need cleaning or part of the loom is shorting through abrasion. Common places are where the loom bends around the engine block. Search for rubbing on the loom insulation.

Thank you for that! Illuminating - no pun intended!

 

[Lancelot]

Don't know you vehicle but a quick look at the wiring diag's available on landrover workshops site does show the heater blower and sidelights share a common earth point.. (K108. 0550)
Fuse 18 serves the sidelights so you have a short somewhere on that circuit..

Roger that - I will check in the morning (now dark as pitch) prior to my oil change!

Fishing going well, no bites yet but many happy hours.

Many thanks.

 

[madmechanic 954]

Roger that - I will check in the morning (now dark as pitch) prior to my oil change!

Fishing going well, no bites yet but many happy hours.

Many thanks.

Are you still having a problem on your rear side light .. working when it .. feels like ....??... and could there be a connection between fuse for the side lights blowing and your rear side light fault .. as in the positive supply to the light shorting out ..causing the light not to work and also blowing the fuse for that circuit.. only now the fault is getting worse .. before the light would just work when it felt like .. but now it is blowing a fuse .. rip out the lamp unit and check the bulb holder for a reason for a short to earth...

 

[Lancelot]

Are you still having a problem on your rear side light .. working when it .. feels like ....??... and could there be a connection between fuse for the side lights blowing and your rear side light fault .. as in the positive supply to the light shorting out ..causing the light not to work and also blowing the fuse for that circuit.. only now the fault is getting worse .. before the light would just work when it felt like .. but now it is blowing a fuse .. rip out the lamp unit and check the bulb holder for a reason for a short to earth...

Cured! The rear side light has been good for weeks now and remains unaffected by the latest shenanigans. The bulb holder is good .

Thank again.

 

[madmechanic 954]

Hullo!

Does anyone have an idea why Fuse18 blows so frequently, (instrument panel illumination and side light)? Yesterday it blew as soon as I turned the heater on heading down a mountainside in Turkey in the rain - at least it was not the wipers!

and i am will to say you probably had your lights on .. and putting your heaters on were not connected .. it just seemed as if the fuse blowing and the heater being turned on at that moment.. were connected .. if you follow what i mean ..and if you can .. well you are just as mad as me...

 

[madmechanic 954]

Cured! The rear side light has been good for weeks now and remains unaffected by the latest shenanigans. The bulb holder is good .

Thank again.

then best i think about it ....

 

[Lancelot]

and i am will to say you probably had your lights on .. and putting your heaters on were not connected .. it just seemed as if the fuse blowing and the heater being turned on at that moment.. were connected .. if you follow what i mean ..and if you can .. well you are just as mad as me...

I am sure if we were out for a pint you would look like the sane one... You are right, heater and light fault appear to be connected - literally and metaphorically!

 

[madmechanic 954]

I am sure if we were out for a pint you would look like the sane one... You are right, heater and light fault appear to be connected - literally and metaphorically!

just checking fuse path .. fuse 18 says headlamp .. but i will keep on looking just to see what fuse 18 can or does control .. but it seems your dash lights are out .. but the heater blower motor is on a different fuse path ... i would think so i will look first and then ask more questions ...

 

[madmechanic 954]

So fuse 18 for what i can see at the moment does the left hand side lights and the dash .. so the fault is on the left hand side ...???or behind the dash .... to be continued ...

 

[Lancelot]

So fuse 18 for what i can see at the moment does the left hand side lights and the dash .. so the fault is on the left hand side ...???or behind the dash .... to be continued ...

Fuse 18 appears to be the right hand side on a Left hand Drive vehicle. To be continued!

 

[madmechanic 954]

Fuse 18 appears to be the right hand side on a Left hand Drive vehicle. To be continued!

bloody left hookers ......

 

[madmechanic 954]

Here is the circuit diagram..so fuse 18 feeds track E and F for your light circuit .. track E does the front rhs.. and F does the rear Rhs there is also a feed from fuse 18 to the dash lights..it is not an earth fault .. but a positive supply going to earth .. shorting the fuse supply but is the fault in the side light circuit or the dash circuit .. hmmm...

 

[madmechanic 954]

The problem with faults like yours .. are a nightmare .. page 9 of your travels say you have a fault now on the right hand rear ..where as it was the left that was playing up at first ...what did you do to the right hand side to fix it ..?? or did it fix it,s self .. was it only the rear light that became faulty ..or was it front and rear ..??.. i would be inclined to look at the rear light as the potential cause .. only because it has been a problem before ..unless you could id a definite cause for the right hand side fault when it went faulty last time and you are sure it could not happen again.. because you did.. A ..and therefore it could not happen again ....

 

[Lancelot]

The problem with faults like yours .. are a nightmare .. page 9 of your travels say you have a fault now on the right hand rear ..where as it was the left that was playing up at first ...what did you do to the right hand side to fix it ..?? or did it fix it,s self .. was it only the rear light that became faulty ..or was it front and rear ..??.. i would be inclined to look at the rear light as the potential cause .. only because it has been a problem before ..unless you could id a definite cause for the right hand side fault when it went faulty last time and you are sure it could not happen again.. because you did.. A ..and therefore it could not happen again ....

Phew! Thank you for those diagrams.

The rear problems have been resolved - I took both units part, cleaned the clag off which comes up into the aperture from below, (particularly if mud-plugging), used a little WD 40, replaced the bulbs and checked the earth terminals. No more trouble.

Today I found this hiding beneath the bonnet:

 

[Lancelot]

Look … a broken circuit. The yellow and black wires appear to have become separated. Any idea which circuit that is? Could this be the culprit? I will reconnect and see! (I know, I never ask easy questions...).

 

[jenks69]

my guess would be that's setup for the headlights / sidelights to run off relays instead of all the power through the main headlight switch. (Of course 100% guess work here).

 

[madmechanic 954]

Look … a broken circuit. The yellow and black wires appear to have become separated. Any idea which circuit that is? Could this be the culprit? I will reconnect and see! (I know, I never ask easy questions...).

No ... do not connect them together ...neither you nor i know what they are for .. the problem of a fuse blowing is that the power from the switch is going to earth before it should do... pos+feed from the battery goes back to the battery ..and the neg- terminal as an earth return ... a loop as such ..but if you were to just join the two feeds together it would spark and get hot .. but if you feed the pos ..side to one side of the bulb (the center pole of the bulb holder )the power runs through the filament and then to the side of the bulbs metal casing and then back to earth .. and the battery ... loop completed .... your problem is that the pos supply to the bulb is not going through the filament .. but direct to earth .. there fore it will spark and get hot ... so a fuse is added to the pos .. supply so that if it goes wrong and the pos .. goes direct to earth the fuse melts .. ie popped fuse ...9 times out of 10 the bulb or the bulb holder is the problem for the short to earth .. even more so if the horrible aftermarket bulb holder are used .. or cheap horrible bulbs which seemed to have a bad habit of the bulb terminals/poles shorting to the bulbs metal casing .. causing the pos.. supply going direct to earth -...and not through the filament .... resitance and all that ..... so yet again yes it is an earth problem but of a different type ... instead of the pos ..supply going through the filament and back to earth .. and the neg side of the battery ..in most cases the bulb will not work because the earth return is not there so the loop of the circuit can not be completed .. clean up the earths .. or add another and the circuit can be completed .. you how ever have the other earth type fault .. in that the ... i do not know how to explain what happens resistance wise and why the bulb lights .. but your fault is the pos supply is finding the path of least resistance... a short to earth to try and complete the loop ... .. i hope this makes sense as such ..