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Momentary electrical Cut out/reset under hard driving

Ed Hodson

ClioSport Club Member
Car - My 2005 182 FF

This has just recently started happening, but I've found that when braking very hard, or accelerating hard in tricky conditions (such as a high speed, off-camber corner, losing traction), I've occasionally had what I'll describe as an electrical reset.

I felt no interruption to power delivery to the road, but the first time it happened was at night, I had my high beam lights on and radio on and traction control was on and did kick in (this was where I was going around the high speed off camber corner). The problem was really obvious because my lights switched from high beam to the regular dipped beam, the radio went off momentarily and when I looked at the dash, the whole thing had lit up (in the same way that it does when you start up the car). I carried on driving, all the lights went off after a moment (as they do when you start up the car) and all was normal.

I thought that the traction control might have been messing things up, so I've been driving with the traction control off, but I've still managed to get the same problem to happen occasionally. When the problem happens, the traction control is switched on again, which I can see being really annoying for my upcoming track day at Cadwell Park.

With my theory being that it's a momentary electrical cutout, I've done the following:

  • Battery - secured it firmly (I have a tiny, lightweight lithium battery - see here)
  • Battery connections - checked that they're absolutely solid
  • Big white plug - checked it (no corrosion at all) and cleaned with contact cleaner. Made sure firmly connected again
  • Relays - Checked them all for corrosion. They're all in great condition. I cleaned all with contact cleaner anyway
  • Connector plug to throttle body - Found this was slightly loose, it's now firmly connected and held with wire

Has anyone else experienced this? Any suggestions for anything else that I can do?

Thank you,



ClioSport Trader
  Clio16v/Zoe Z.E.50
Morning Ed,

It could still be the battery, so don’t fully rule it out just yet. How is it mounted? Have you checked the main harness electrical earth, at the back of the upper gearbox case? What about the secondary loom to chassis earth, behind the passenger headlamp (this one also goes straight back to battery). It sounds as if something is 100% moving and pulling on a wire under extreme loads.

Ed Hodson

ClioSport Club Member
Hi Mick,

The battery (weighs less than 2kg) is mounted with cable ties. It's solid, but admittedly still not as firm a a lead acid battery (bolted down) would feel.

I went to Cadwell Park on Weds evening and the problem persisted. It didn't spoil the evening, but it was irritating. If you take a look at this video, from 1min 30sec, you'll see me taking Barn badly, putting extreme load on everything, leading to the momentary "reboot" of electrics:

You'll notice that the climate control goes off for a moment and you'll see all the dash lights light up, then go out again.

I think this will be my plan:

  • Put my lead acid battery back in, bolted down
if that doesn't fix it....
  • I'll check all of the earths and connections that you've mentioned

As you say, it's got to be something that's moving/being pulled under extreme loads.

Thanks again - I'll keep you updated!



ClioSport Trader
  Clio16v/Zoe Z.E.50
Looking at the video, I think it’ll be either your battery moving or the battery itself.


ClioSport Club Member
  Clio rs 172 p2
have u relocate battery ? in stock position the battery may cut the possitive cable sime like the cell to starter .it also may hit the ground (shell)