Quatermass

New Member
My 300Tdi's "warning triangle" light on the hazard light switch won't come on. Hazard function, indicators, dash lights etc all work fine.

Tried replacing switch with both a new Britpart cheapo one and a new Lucas pricey one but still no joy.

Tried disconnecting the new switch completely and put 12v across its side terminals (the ones which light its internal bulb) and it lit up fine.

Checked the vehicle's feed to those same terminals and it was fine, albeit more like 11.8V.

Plugged switch back in, no joy.

Is the switch's internal bulb really fussy about getting a full 12V? Could it work once and then fail? Or have I missed something else?

I am aware of the endless fun and games to be had with LR indicators/relay/hazards/switch etc but this seems like an odd one...
 
I did wonder whether a connection became dodgy only when the switch was fully reseated. But I'd be surprised - I also tried testing it pretty much in situ with all the connectors almost completely on, just leaving enough space to get a probe in, and all the earths/supplies were fine. Argh!
 
I did wonder whether a connection became dodgy only when the switch was fully reseated. But I'd be surprised - I also tried testing it pretty much in situ with all the connectors almost completely on, just leaving enough space to get a probe in, and all the earths/supplies were fine. Argh!
Might be doing it down the line somewhere.
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Sounds like you have voltage but no current.
You say there is 12V present try testing it with a piece of wire and a small bulb ...
May do some more testing come the day when I properly sort out the previous owner's hideous rat's nest of dash wires. Meanwhile no MOT worry at least so I've reseated it for now and the thrilling mystery will remain. Did at least swap the sh1te plastic fascia for metal whilst I was there...
 
assuming the square type have you connected the black/red and a good earth to the two side tabs for the warning lamp
 

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I did wonder whether a connection became dodgy only when the switch was fully reseated. But I'd be surprised - I also tried testing it pretty much in situ with all the connectors almost completely on, just leaving enough space to get a probe in, and all the earths/supplies were fine. Argh!
I had one that did indeed become dodgy as it was reseated. I proved that by pulling half the dashboard apart, so it could see it go in from the top.

The solution? Three layers of black electrical tape to bulk it up a bit, and now it is firmly in place without being fully flush, and it works...
 
My 300Tdi's "warning triangle" light on the hazard light switch won't come on. Hazard function, indicators, dash lights etc all work fine.

Tried replacing switch with both a new Britpart cheapo one and a new Lucas pricey one but still no joy.

Tried disconnecting the new switch completely and put 12v across its side terminals (the ones which light its internal bulb) and it lit up fine.

Checked the vehicle's feed to those same terminals and it was fine, albeit more like 11.8V.

Plugged switch back in, no joy.

Is the switch's internal bulb really fussy about getting a full 12V? Could it work once and then fail? Or have I missed something else?

I am aware of the endless fun and games to be had with LR indicators/relay/hazards/switch etc but this seems like an odd one...
I had the same thing and after doing some investigating i found the connector on the back side of the switch was fried... ive been looking for that plug everywhere on the web but cannot seem to find one without ordering a whole new harness... anyone have any idea where i can find one? It's the connector that plugs into the Hazards switch. Thank you
 
I’ve seen this one, cannot seem to find it for sale though even with the C096 part number… but this IS the one!
 
I can supply the 8-way Lucas-Rists connector for the hazard switch.

The connector housing (13H9237), supplied with 8 x terminals and a cavity blank pre-installed in cavity 6, they are £9.95 + P&P.

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