renault megane 1.9 dci - Lights dimming whilst driving

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Sun 28 May 2017 15:04
renault megane 1.9 dci - Lights dimming whilst driving - KCSRenault

Hello there folks,

I have recently being having problems with the lights on my car, when the car is first turned on and the headlights are switched on, they get much brighter after 30 seconds or so. that was okay to deal with.

But recently i have noticed how terrible my lights are when they are on dipped and have on some occassions watched them go down, like when a battery runs out on a torch.

The car still holds a charge okay and starts as well as can be expeccted for an old dci,

Anyone have any ideas at all?

Many thanks

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Sun 28 May 2017 16:02
renault megane 1.9 dci - Lights dimming whilst driving - Railroad.

Sounds like a fault with the charging system, battery or wiring. Do a volt drop test from battery + to the alternator B+. With the engine running and all electrical loads switched on the voltage difference should not be more than 0.5v. If it is you have a poor connection between the battery and alternator. Do the same between battery - and the engine block. Again a voltage difference of more than 0.5v means you have a poor engine earth.

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Sun 28 May 2017 18:35
renault megane 1.9 dci - Lights dimming whilst driving - bathtub tom
when the car is first turned on and the headlights are switched on, they get much brighter after 30 seconds or so. that was okay to deal with.

That was probably your glow plugs. They draw a high current initially, but switch off after a while.

But recently i have noticed how terrible my lights are when they are on dipped and have on some occassions watched them go down, like when a battery runs out on a torch.

Do they brighten again if you rev the engine?

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Mon 29 May 2017 13:08
renault megane 1.9 dci - Lights dimming whilst driving - Peter.N.

Check that you have around 14.4 volts across the battery with the engine running, if much less you probably have a faulty alternator.

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Tue 30 May 2017 13:28
renault megane 1.9 dci - Lights dimming whilst driving - Cyd

Get your multimeter out and get testing.

https://www.youtube.com/playlist?list=PLOaePmzqZNJ24dTPG6x570Pze_D4Cxy6F

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