HELP! - Interior roof spotlights stopped working

[Oggy172]

Hi all,

So we got a pre-converted camper last year and have barely used it - getting it ready for when lockdown ends and noticed the roof spot lights had stopped working.
As we didn't do the conversion, I don't know a great deal about the wiring, although it looks very amateurish.

There was a switch on the B Pillar which she was convinced she had knocked & true enough, upon removal, one of the wires had snapped. I resoldered this back into a new spade connector.... However, still we have no lighting.

Onto my diagnosis thus far:

Starting from the leisure battery - the main switchboard (?) which turns on the fridge, lights & water pump etc gets 12v, everything works ok on this and we get an LED on the lighting switch. so this appears good.
The back of that switch has:
<12v>
<switched live?)
<Ground/Earth>

The middle pole on this switch runs through a 15A and possibly a 10A inline fuse, round the back of the Transporter and into a relay by the rear left tailight. I checked with a multimeter, and it does get 12v when it enters the relay.

... and now where I'm stuck and need your help

There are 6-7 outputs from this relay but I am unsure where they should go, where they do go and if somethings awry.

..... So working back from the spolights

I have continuity from the lights to 2 of the 3 wires at the B Pillar switch, connecting these to a 9v gives me LED's - so with that I have deduced the issue must be from the relay -> B Pillar which is the 3rd wire.

Is anyone aware of a similar setup or any advice how I can diagnose this further and rectify? I'm guessing it should provide 12v to the +ve wire (via the B Pillar switch) for the roof LED's but it's not getting 12v and connecting the wires directly didn't give me any lighting either.

Any help greatly appreciated.

 

[Oggy172]

The relay is a Maypol TEB7AS which looks like thats for the tow bar? would it be spurred from here?

 

[Deaky]

Is the switch a 3 way? Or a 2 way with an led light on it? Did the lights come on with the doors or are they only operated via the switch?

Your relay is a bypas relay module for your towing electrics. It’s nothing to do with the interior lighting although whoever installed the lights may of spurred off the +12v feed to it.

 

[Oggy172]

@Deaky - the lights only came on by the switch only.

Switch:

 

[Deaky]

Have you got a pic of the wires at the switch.

 

[Oggy172]

It's a bit dark but here we go....

There's a solid red and red/black wire from above the B Pillar (continuity to LEDS +ve/-ve) - attached to a 9v battery the lights work, so the problem isn't B Pillar upwards IMO.....

from the floor I have another red/red black combo (below), the red/black was paired/spliced with the red/black mentioned above... This gave continuity to the leisure battery -ve terminal.




I don't have photos of the wires northwards as I've rotated the seat back so she can drive it in the morning but as above, they seem to check out.

Thanks

 

[Deaky]

So the red/black -ve in your hand should connect to the -ve on the switch and the red/black-ve in the b pillar. The red led +ve in your hand should connect to the centre pin on the switch.
so your just missing a +12v from the leisure battery.

the wire that goes to the relay from the switch is that +12v?

 

[Oggy172]

From the main switch - yep, 12v to relay.

 

[Deaky]

So you have 12v from the leisure battery to the switch then spliced on to the relay?

can you verify the switch is working with a tester?

 

[Oggy172]

I have 12v from leisure battery -> main 5 bank switch -> centre pin on 5 bank switch -> relay.

B Pillar switch has continuity between centre pin and the 'switched' side, alternating continuity when the switch is flicked - which sounds like it's doing what it should!

 

[Oggy172]

@Deaky - could you advise further please if possible?

Thanks

 

[Deaky]

Not sure exactly what a 5 bank switch is. Do you have any other pics of the installation?

 

[Oggy172]

Sorry that's the isolation switch from the leisure battery (has switches for water pump, lights, fridge etc)

 

[Oggy172]

I've tried to visually represent it here:

 

[Deaky]

[Are you sure that the middle switch on the panel ever operated the lights? the towing bypass relay is nothing to do with the interior lights, is it possible that the +12v on the towing relay was continued on to the switch on the b pillar and the wire has fallen out of sight when the switch was broken?

 

[Oggy172]

No, I'm not sure.
They worked when we bought it, now they don't and popping off the switch had the snapped wire just a few mm from a broken spade connector on the b Pillar switch.

Logically we thought this was the root cause.

There are 4 wires to the switch and the two upper ones definitely are +/-ve to the lights, validated by the 9v battery test.

As I understand it, that then means 12v and gnd to the switch panel should be the lower two wires from the b Pillar? Could I just route a new 12v from the switch panel to the b Pillar??

 

[Deaky]

That would be your easiest solution, the original must be broken somewhere

 

[Pauly]

Is it possible the broken wire shorted against the chassis and blew a fuse ??

 

[Oggy172]

I checked the two inline fuses from the switch panel and they're fine, as I said I got continuity from that to the relay (appreciate the relay isn't directly relevant to the lighting) - so that circuitry is good.

As I'm working at the minute I won't get any decent time / lighting to take another look at it until Saturday - just want to get in there and get it fixed on the first dry day - I'm not completely alien to wiring and circuitry so the work doesn't phase me, just want to make sure I'm doing the right thing first time as I could've easily lost a lot of time looking in the wrong place if I wasn't careful.

Thanks for your replies, I'll report back at the weekend with how I fare.

 

[Oggy172]

On the switch panel, what's the middle pin for?
I have:
Top pin (vcc in?)
Middle pin -> Fuse -> (I assume the accessory) - (vcc out?)
Bottom pin (GND)