Electrics had nervous breakdown 406Hdi

Talk about the 406's electrical system, what wires do what, how to add extra functionality, etc.

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PeterN
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Electrics had nervous breakdown 406Hdi

Post by PeterN »

After around 4 years of relatively trouble free motoring I suddenly have electrical gremlins. The first thing was that the fuel gauge was alternating randomly between half full and empty with the light on, in addition to that I now have a speedo and rev counter that go between normal and not working or full scale, the panel lights are going on and off and the heater blower doing the same. more worryingly the blower comes on without the engine running.

It sounds like spikes upsetting the electronics, it was suggest that the ignition switch might be faulty which I thought was possible but it seems not. I have removed the fuel tank sensor and it appears to be OK, sometimes the gauge goes up and down when I move it at others it doesn't, if you hold it in the full position it only reads about half.

It has a new battery and is reading 14.4 volts with the engine running. It drives OK except that that the power varies as the fault comes and goes.

Help!

Thanks
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steve_earwig
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Re: Electrics had nervous breakdown 406Hdi

Post by steve_earwig »

Hi Peter, no idea what year your car is but this looks favourite viewtopic.php?f=10&t=12118&p=107150&hilit=crazy#p107150
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PeterN
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Re: Electrics had nervous breakdown 406Hdi

Post by PeterN »

Thanks for that, I don't think mine is damp but will check. Its a 2001 incidentally

Peter.
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Re: Electrics had nervous breakdown 406Hdi

Post by steve_earwig »

2001 means it could be either, I can't remember if the damp carpet syndrome affects semi-mux 406s but it must be worth a gander in any case.
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PeterN
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Re: Electrics had nervous breakdown 406Hdi

Post by PeterN »

I will certainly have a look.
PeterN
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Re: Electrics had nervous breakdown 406Hdi

Post by PeterN »

Many thanks for referring me to that thread, it was spot on. I had never noticed any dampness in the car until I took the carpet up, one of the connectors was actually in the water. I now have to find where its getting in.

Peter
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Doggy
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Re: Electrics had nervous breakdown 406Hdi

Post by Doggy »

Good news!

Usual culprit is sunroof drains, (if you have one)? Let us know, it's a really easy fix.

Others have had water gather in the sills or bottom of the doors leading to them spilling inside on steep hills.
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
PeterN
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Re: Electrics had nervous breakdown 406Hdi

Post by PeterN »

With all the rain we have had I'm not really surprised. Its wet in the rear as well I have now noticed, no smell of damp in there so I think its only recent. The seal on the edge of the rear door fell off sometime ago, I wonder if its getting in there, I have replaced it now. I will have a good look round later. It doesn't have a sunroof, were those the drains?

Peter
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Re: Electrics had nervous breakdown 406Hdi

Post by steve_earwig »

Glad you found the problem, I hope the connector's not too fubarred.
PeterN wrote:The seal on the edge of the rear door fell off sometime ago, I wonder if its getting in there, I have replaced it now.
When they're missing there's a nice row of little holes that let water into the sills. That's bad enough but if the drains are blocked (like they often seem to be) the water will work it's way inside, plus the sills will rot from the inside-out - viewtopic.php?f=18&t=20854&hilit=sill+drain
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PeterN
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Re: Electrics had nervous breakdown 406Hdi

Post by PeterN »

The connectors are all nice and clean as is the floor so the water obviously hasn't been in there long, as soon as I removed the water everything went back to normal, haven't cleaned the connectors yet. I have put the seal back on the door but its not keen to stay there, I will have to glue it when its all dry.

Peter
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