Yeah they don't do any of that, turns out it wasn't just me being thick, they are indeed all knackered...
Though I'm wondering if the ~80 miles in limp mode with them stuck on permanently might've finished them off lol! As I understand it, the ECU uses a backfeed to switch them off, but as theyre linked in series, if just one is failing, the ECU doesn't get the signal to switch them off. They usually only come on in 40 second bursts.
Either way, have been no issues since fitting the new ones so all good there. Cheap fix too tbh.
Though I'm wondering if the ~80 miles in limp mode with them stuck on permanently might've finished them off lol! As I understand it, the ECU uses a backfeed to switch them off, but as theyre linked in series, if just one is failing, the ECU doesn't get the signal to switch them off. They usually only come on in 40 second bursts.
Either way, have been no issues since fitting the new ones so all good there. Cheap fix too tbh.