I'm trying to track down the fault on the rear fog light on my Marea Weekend 130 HLX.

I've checked the bulb, and it seems fine, so was trying to understand the wiring diagram so I can set about it with a multimeter. Problem is I can't quite get my head around how the fog lights are powered. There seems to be permenant lives connecting to permenent neutrals in the diagram - which is just confusing the hell out of me. :bang:

Can someone clear the fog away from my view of this diagram... and explain where I should be prodding the multimeter probes?

i would presume your car has front and rear fog lights,best to have engine running and have headlight on not main beam which shows blue light on dash,possible 2 locations for both fog lamps,1 could be on end of light stalk and other a flick switch on dash.you will have to turn or flick to see what operates the front so you can rule that one out,and go to the other switch.check block connectors in rear for green stuff causing bad connections.

at the rear connectors on lamps you should have 2 feeds as the side light will have 1 feed or if twin side lights 3 feeds as the third will be the fog lamp when switched on.

I know how to operate the lights, but the rear fog is not working. Front fogs are working fine. The other lights on the cluster are working fine too so it's not a bad earth at the cluster.

Does anyone know if the front & rear fog light fuses are shared with any other systems?

I'm hoping the fog lights are all they do - and that it is simply a failed fuse.

You got a bog standard 12v test lamp? Clip the neg to chassis and probe the top of each fuse on both sides if it lights touching one side and not the other its blown I find It faster than trying to translate the hand book

Is it obd2 compliant? And body computer based? If yes you can test relay with FES

does the fog light tel tail light up on the dash?

Fog light tell tail doesn't light up, but that is powered from a feed from after the rear fog light relay. I've got a multimeter for testing with.

I'm not sure on the ODB2 compliancy but I don't have a laptop to test with.

You found the relay? Can you hear it switching? Can you swap it with an identical one to test ?

The relay is in the switchpanel itself. It has a soft button (or the front fogs, but I kinda remeber the front having a real latching switch with beefy traces on the pcb). You can check if the relay is getting power by probing the contacts with the multimeter gound on the cigarette lighter ground or something (you see continuity to the earthpoints that way). Got a whole spare panel for myself thats been taken apart.

Neverth said:

The relay is in the switchpanel itself. It has a soft button (or the front fogs, but I kinda remeber the front having a real latching switch with beefy traces on the pcb). You can check if the relay is getting power by probing the contacts with the multimeter gound on the cigarette lighter ground or something (you see continuity to the earthpoints that way). Got a whole spare panel for myself thats been taken apart.

Click to expand...

You remember very well!

The front is a real latching switch, the rears are a passing contact with an electronic latch. The relay isn't being activated by the switch. I've tested the switch and it is working (pressed in all contacts are live). I've manually closed the relay and the fog light works.

So, the issue is either with the coil of the relay, or the resistor and ICs that form the latch. I can't get into the contacts on the relay to test, and to get the PCB off the front switches looks like it would need all the LEDs un-soldered. It looks like I need to find a working replacement switch panel... and fast!

Until then, my rear foglight is activated by sticking a bit of paper into the relay to hold the contacts closed.

do i see a burnt out micro resistor?

between the white plug and first relay bank of 4 resistors (little black things with numbers on) third one down looks to have fried

Andy Monty said:

do i see a burnt out micro resistor?

between the white plug and first relay bank of 4 resistors (little black things with numbers on) third one down looks to have fried

Click to expand...

I thought that too, the numbers were partially obscured. My attempts at clean up to read them easier didn't make it any better. I performed a resistance test across the resistor and still got a reading. I think that resistor is protection for the switch illumination LED. Could be wrong though as I've not been able to see the other side of the PCB.

It is the resistor for the foglight led, reads 561 and measures 280ohms across (two parellel resistors). Had the leds removed and took the plastic off, but there was nothing interesing on the other side, just traces. The chip has some writing but needs proper magnification to read it so no idea.

Just a quick question. Did you have dipped beam on when you test the thing? It wont go on with just parking lights...

Yes, had headlamps on dipped beam.

I've seen a few Marea on ebay being broken, but none of the sellers have responded to my emails asking if the part is available.

Thinking of dropping the part into a auto-electricians to see if it can be fixed.

Hellcat I might have one but not sure if it has the alarm led, will have look and let you no...

Hellcat sorry mate no luck yet, have one more pain in the rear place to check.
Will look tommorow mate...
Having a few issues with mine at the mo.

Hope they're not major headaches!

Nothing breaking the rear door quater glass won't solve??

Remember when dehandling and delocking your car completely to have a back up plan first,
or you could do it in reverse like I've done, back up plan after the event.

I'm going to check for the fog light bit now.

Oh dear. The de-handled look is rather nice, but knowing my luck and old car's electronics - the chance of getting locked out the car is too great for me!