C209 3rd brake light testing

[grahamcol]

Hopefully someone can help.
Just bought a genuine replacement and would like to test prior to installing as current one still works most of the time. Does anyone know which of the two connection pins on the unit is positive / negative as l don't want to cause any damage. Or maybe it doesn't matter?

 

[EmilysDad]

I doubt it'd matter, if it doesn't work, swap the polarity of your power supply.

can't you plug it in to test first before you fit it?

 

[grahamcol]

Thanks. I don't want to do any dismantling yet, just need to test it in case l have to send it back (straightaway). I've just used my multimeter on diode test and it reacts, still not sure which is pos / neg though.

 

[EmilysDad]

Thanks. I don't want to do any dismantling yet, just need to test it in case l have to send it back (straightaway). I've just used my multimeter on diode test and it reacts, still not sure which is pos / neg though.

you won't break it if you put your supply the wrong way round, it just won't light up.

 

[grahamcol]

That's what l thought actually and you're right as I've just tried it and it didn't work initially but did once l reversed the connections. Thanks!