lost electrics

[AlanC180k]

Hi can anyone help went out the other day in my c270 firstly revs started to go up and down then slight clicking noise then everything started flashing ie airbag,esp,dash lights,headlights switched off and restarted all ok then went out again in the evening when stopping at traffic lights it happened again but this time lost all electrics total darkness battery terminals ok after about 5 minutes it came back to life and was ok for rest of evening any help would be appreciated thanks

 

[Dieselman]

Loose earth strap?

 

[Brian WH]

Have you driven through any floods recently, as this was what happened to my flooded car. Hopefully it is a dirty or loose connection as above.

 

[Tinkerer]

I would check the battery then the alternator, they do not like the voltage dropping.

 

[AlanC180k]

Thanks everyone not been in any floods checked earth strap thats fine so will have to get battery and alt checked battery is mb one so might be as old as car

 

[grumpyoldgit]

Might be worth checking that the ECU isn't wet. It's located along side the underbonnet fusebox. There's a thread on here somewhere about similar strange happenings with the electronics on a C270 but I think he had problems starting it as well and it turned out that the ECU was soaking wet. He dried it out in a warm place over night and the problem was fixed.
Have you noticed if it happens in any particular circumstances? i.e. when braking of facing downhill. If there is water ingress of the ECU, it could be sloshing about inside.

Get the battery and alternator checked first though.