Fiat Ducato 2.3jtd 2005 dipped beam and fog fail, but comes on after 5 mins!!!

[mightyworthit]

Hello all, thank you very kindly for reading my post.


Fiat Ducato 2.3jtd 2005 swift motorhome.


Ok..I have lost my headlights dipped beam and fogs....but the funny thing is they come on again after 5 mins driving! Then if I switch the engine off I lose them again..then drive for 5 minutes then they come back on.


I sort of got used to this, but just recently they went altogether and now I have no front dipped headlights and no rear fogs!!


Obviously I have checked all bulbs, fuses, all the relays that I can find associated with the lights, block connectors, and multi-metered the feeds to the light cluster (nothing reading).


Several months ago I retro fitted a reverse camera, I am wondering if it is this wiring that has mucked up things.


I was told by a friend that I should replace the light switch stalk, but this is expensive and would like to check other possible causes first.


Please please I am at my wits end. Could it be a faulty earth, would a faulty headlight switch stalk effect the fogs as well (switch is on the dash)?


Many many thanks Tim.

 

[telectrix]

could well be the switch as the fogs are slaved off the dipped beam feed. check for volts appearing at the fog switch when dipped beam is selected. if not, then it's likely the stalk. my mate's got a ducato van. i'll ask him if he has any ideas. a stalk from a scrapper is probably your best bet.

 

[PEG]

Hello there,your stalk will be switching a relay,for those main lights,so if they are fading after a short while,i would be looking at the higher load side,ie; between the relay and headlight lamp.

Could be as simple as crusty pins on a relay,gammy multi-pin connectors,or cruddy earth connections...

I would recommend initiating the fault,before fault finding,as this makes identifying the reason,easier.

 

[mightyworthit]

Hi thanks for the reply
I am going to check the feed from the switch stalk if I can. It means locating the wire that comes from the stalk to the body computer. I think I just have to check that when the dipped beam is selected there is a positive supply in that lead.

What is the best way o identify this lead that comes from the stalk to the body computer...do you think taking off the steering wheel to access the stalk cluster and would make this easier?

 

[PEG]

Hi,this may well give better access,just bear in mind things like snail ribbon cassettes,and the wheel air-bag. You DO NOT want to be jabbing a conventional style tester about,as there is a possibility of damage to todays' sensitive electronics,and also deployment of devices which would give you more than a surprise:shocked:

Some control systems use "signal" feeds,and as such,will not always give meaningful voltage readings. Modern CanBus node points may have many benefits,but being fixed in the wilderness,using a bit of speaker wire,is not one of them!

I am more than capable to line-trace any system,even without diagrams,given enough time,but with plant,vehicles and some equipment,a good old google on the respective forums,can tease an answer from folk who have already done the diggin'...so to speak.

Any chance you could get an auto-electrician to have a gander? He may be cheaper than a guessed at part purchase,from those less able.

On a similar vein,i had a camper-van only today! It was brought in desperation,having only one sidelight,and the owner plus two others,having failed to fire-up the remaining three....

A fuse,and two lamps later,everything was groovy. I think a fumbled blown bulb change,had blown one fuse,which then got swapped to the other side, the other lamps were then "checked", refitting them badly...

Please let us know your progress :mellow:

 

[mightyworthit]

Thanks for the reply its very kind of you.

First of all Ive realised that my Ducato does not have body computer! its a 2nd generation model rather than a 3rd gen.

I located this wiring diagram after digging around the Ducato forum and downloading the eLearn workshop manual.



I then dug around further to get the translation of the wire colour codes. (h is grey apparently!)

I am waiting on my 12v bulb tester to be delivered (£4 from amazon) which should then hopefully allow me to test me the stalk switch.... checking live in and switch live out...as indicated on the above diagram. Hopefully i will not have to take the steering wheel off to do this

I am hoping that it is the stalk switch hub thingy. There are replacements on ebay for £35.

I replaced similar on my peugeot earlier in the year, not due to a fault but to upgrade my trip computer functionality (it worked!)

IF it isnt this I will methodically work my way through the fault diagnosis flow chart also provided in my Elearn workshop manual.

Any comments???

 

[PEG]

Hi again,your diagram is only part of the system,and the index to the nomenclature,is omitted...but it looks like you have an ignition switched feed from BO99 via handed fusing at F14 and F15,with the latter also feeding the foglight circuit.

You need to find relay T02,and bridge pins 30 and 87,which should give you dipped beams and fog lights.

If the relay tests OK,you need to travel "upstream",to the enabling circuit,H001 in one direction,and H090/H005 etc,in the other.

Post a bit more of the headlight circuit,and component identity list,for more remote ramblings!

 

[mightyworthit]

yes i have this pic....

This is great stuff thank you so much PEG.



Or should there be more pics similar to the first?

 

[mightyworthit]

here is the wiring diagram for the rear fogs


and the location diagram of same



Could I ask...do you think it is significant that when i first switch the ignition I had no dipped beam but after five minutes driving they would mysteriously come on (but last journey I have lost them altogether)...does this point towards a faulty stalk switch?

 

[mightyworthit]

And the diagram for the location and description of the dipped beam parts.
(tried posting it earlier and it doesnt seem to have come up...sorry if this is a duplicate!!!)