Technical NS rear high mounted light not working

[John68whittock]

I have a 2016 Swift 624. The NS high rear light has stopped working. Checked lamp, re made off connector spades. 11.6v measured when open circuit (bulb removed) and 0v with bulb. Checked earth continuity to OS high rear light fine. Swift manual says voltage is fed by Y203 Fiat connector to L12. But I cannot find any further info. Its a Fiat Ducato 2.3 130bhp base. Worried an ECU fault. Any help would be greatly appreciated.

 

[chris3234]

I have a 2016 Swift 624. The NS high rear light has stopped working. Checked lamp, re made off connector spades. 11.6v measured when open circuit (bulb removed) and 0v with bulb. Checked earth continuity to OS high rear light fine. Swift manual says voltage is fed by Y203 Fiat connector to L12. But I cannot find any further info. Its a Fiat Ducato 2.3 130bhp base. Worried an ECU fault. Any help would be greatly appreciated.

The car t you have voltage at all means it's unlikely to be a an ecu issue


Mostly likely a bad earth or connection somewhere down the line

 

[John68whittock]

Thanks for reply. I have worked out I did accidentally start van with EHU charger connected as the battery was low at the time. I am concerned this could be the cause? Does anyone have a Y203 connection diagram for a 2015 van they can share?

 

[Communicator]

Thanks for reply. I have worked out I did accidentally start van with EHU charger connected as the battery was low at the time. I am concerned this could be the cause? Does anyone have a Y203 connection diagram for a 2015 van they can share?

I cannot see why starting the engine with EHU connected should cause a problem.

I fully agree with chris3234.

I keep repeating that modern multimeters are very sensitive, and can give a misleading, acceptable reading via a high rsistance connection, beware!

One problem to bear in mind with an MH is jump starting. If the split charge relay becomes operated, and a start is attempted, large currents can flow from the hab battery, and fry the habitation 12V electrics before blowing a fuse, which may have been uprated.

Y203 did not convey anthing to me. Did an internet search. Returned a mention of Converters & Upfitters Manual on this Forum. See Dowloads at top of page. OK it is for X290, but should help. See section 3.26 onwards at page 98.

However if weather allows look under the LH rear of your vehicle for a junction box? I remember reading of a similar problerm being traced to poorly made crimp connections half pushed into the chassis.

Please post the resolution of your problem on this thread, for the benefit of others.

 

[John68whittock]

Thanks communicator much appreciated. I have the mentioned convertor manual now. Very useful. I can see on the Swift manual that L12 n/s high rear light (not working) is parallel on the +12v high line with L4 rear light and L9 number plate light which are both working, so hopefully not computer output. Most likely a high resistance joint as you stated. Having checked out the earth side of L12 against the L11 o/s high rear light as 0 ohms, it is not that side. I am working away for next few weeks so van now back in storage. I will buzz out 12v hi side connection on my return and let you know. Thanks once again.

 

[The Panda Nut]

I can only speak from caravan experience, but bad bulb likely and poor earth unlikely with a high level light. Most likely a bad connection on the light fitting would be my personal suspect. High level lights that dont work mostly require a new light unit. One light out is not going to be ECU related. Test the bulb first, then clean the contacts and if required run a wire from the neg side of the light to earth and see if that makes it work. If it does then the earth would be the issue. Festoon bulbs can wear making contact with the light terminals bad. Also try a new bulb even if the old one hasn't blown. Good luck.

 

[John68whittock]

Still working on this fault unfortunately. Swift Tech Support helping but no good news yet. I am trying to get hold of correct schematic diagrams as the ones in the Tech Manual seem incorrect. I am also trying to find a couple of connectors suggested by Swift to be involved in the wiring. One is a 15 pin connector in the front of the lounge by the room heater unit. If anyone has had a similar issue please contact me. The upper rear lights do not seem to be connected in parallel to the main rear lights as both sides rear open circuit to there main rear lights. They may be driven directly from the Fiat electrics? Any help appreciated

Regards

 

[Communicator]

Hi John,
Some converters use the Converters Panel Option, which is located at the base of the RH "B" pillar. Looking at diagram of that panel has a 15 way connector included. Pin 11 reads "Side markers negative control relay". I interpret that as meaning that it is connected to earth, when sidelights are on. Also pin 15 provides an ignition switched supply via F49. Swift may have used a relay powered by these two pins to control your faulty lights from a separate 12V supply. Pages attached for convenience.

Going back to basics, the electronics will probably be set up for conventional two rear lamp arrangement. Any additional lights would perhaps draw too high a current, and raise an alarm. It would therefore be sensible to adopt the arrangement that I have just outlined.

I am by no means an expert in the above as my x244 is without such complications, any positive contribution is welcome.

( I do have a Saab 9-3 Estate with an RH brake light which sometimes fails and alarms, LED light units, wiring tests fine. I suspect a dry joint on PCB.)

 

[John68whittock]

Hi John,
Some converters use the Converters Panel Option, which is located at the base of the RH "B" pillar. Looking at diagram of that panel has a 15 way connector included. Pin 11 reads "Side markers negative control relay". I interpret that as meaning that it is connected to earth, when sidelights are on. Also pin 15 provides an ignition switched supply via F49. Swift may have used a relay powered by these two pins to control your faulty lights from a separate 12V supply. Pages attached for convenience.

Going back to basics, the electronics will probably be set up for conventional two rear lamp arrangement. Any additional lights would perhaps draw too high a current, and raise an alarm. It would therefore be sensible to adopt the arrangement that I have just outlined.

I am by no means an expert in the above as my x244 is without such complications, any positive contribution is welcome.

( I do have a Saab 9-3 Estate with an RH brake light which sometimes fails and alarms, LED light units, wiring tests fine. I suspect a dry joint on PCB.)

Thank you will check out when I have the time.

 

[HughJampton]

All the following subject to my interpretation.

The wiring diagram(s) look reasonably logical, and the "problem" light is on the same live feed as L4, the N/S Tail Lamp, and L9, an undefined one of the number plate lights. If these are working, I think you can discount any major ECU or similar issue.

It also shares a ground with L15 (only), the High Level Brake Light, so if this is working the fault diagnosis narrows considerably.

The Y203 (actually Y203L4A) Fiat connector is detailed on page 98 of the converters manual you've already been guided to. Whilst the year of the manual isn't relevant, it's very unlikely it has changed for this detail, and the connector is to the rear N/S of the chassis (diagram on the page above). This standard Fiat lighting connector is used to power the lights you have issues with - only the additional side markers (L16-23) are powered by the Sargent-provided electrics, and I suspect triggered from the converters socket (they'd be too much additional load for the standard Canbus).

Subject to all the other lights as above working, I'd suggest a wiring break close to the particular light, a dodgy holder, or a duff bulb.

 

[John68whittock]

Thanks for responses. My worry is when I checked continuity on the 'good' OS lamp there was none between the main rear lamp bulb and the high line (black wire). I have checked both sides earth's as good. Bulbs also checked & replaced with no effect. I have re made off / replaced connectors in NS lamp just to be sure with no effect. What I am confused about is the schematic seems to show the main rear, number plate and high lights in parallel. But the OS readings do not confirm this? I have question Swift on this.

With thanks

 

[John68whittock]

Thanks for responses. My worry is when I checked continuity on the 'good' OS lamp there was none between the main rear lamp bulb and the high line (black wire). I have checked both sides earth's as good. Bulbs also checked & replaced with no effect. I have re made off / replaced connectors in NS lamp just to be sure with no effect. What I am confused about is the schematic seems to show the main rear, number plate and high lights in parallel. But the OS readings do not confirm this? I have question Swift on this.

With thanks

Sorry when I stated high line I meant OS high lamp positive wire. L11 that is.

 

[John68whittock]

Sorry when I stated high line I meant OS high lamp positive wire. L11 that is.

L12 (not working) L9 and L4 are shown in parallel. As is L11, L10 and L8 on OS. This is not showing to be the case?

 

[John68whittock]

Just to let you know fault found and fixed.. it was a high resistance joint in a 15 way connection at the front left hand side of the coach by the heater unit. It seems the Fiat connection goes to a 9 way connection at the rear of the underside of the van then travels up into the van floor. Travels along the van floor to the 15 way connection at the space heater, then up the van pillar to the roof before travelling back down the roof at that level to the OS high lamp then onto the NS lamp. The 15 way connection way at 53kohms. Nominal is 4ohms. Look for a white 0v and brown wire in the 15 way connection which is hidden behind 2 heater pipes.

Thank you to everyone who helped

 

[Veesto85]

Just to let you know fault found and fixed.. it was a high resistance joint in a 15 way connection at the front left hand side of the coach by the heater unit. It seems the Fiat connection goes to a 9 way connection at the rear of the underside of the van then travels up into the van floor. Travels along the van floor to the 15 way connection at the space heater, then up the van pillar to the roof before travelling back down the roof at that level to the OS high lamp then onto the NS lamp. The 15 way connection way at 53kohms. Nominal is 4ohms. Look for a white 0v and brown wire in the 15 way connection which is hidden behind 2 heater pipes.

Thank you to everyone who helped

Are you able to mark the location of the 15 way connector on the attached drawing? Am having similar issues as you and I've had 2 garages look at the problem with no joy thus far! My L12 + L11 (n/s and o/s top rear maker light's), L4+L8 (both the tail light's), L9&L10 (number plate light's) are all intermittently working except L10, it's never worked since I got the MH. Am a bit clueless when it comes to electrics but am hoping some electrical contact spray does the trick or am faced with a 250 mile round trip to get it seen by a swift professional!

Any help would be much appreciated