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Renault Laguna - Renault Laguna 1.9 dci starting issues. - ScoBro

Hi Folks

I'm looking for some advice if anyone knows about dreaded Renaults ??

My Grandads 1.9 dci 130 2005 Renault Laguna is stood alot and hasn't had much use in the last 6 months. We started getting intermittent starting issues over the last few months. We replaced the battery for brand new and today I have put a brand new starter motor on it. It still refuses to start 90% of the time.

Checking battery voltage, with no card in the slot its' between 12.4 and 12.5v

As soon as I put the card in the slot which does all it's vehicle checks (abs, airbags, starts the glow plugs) the volts drop to 11.4 to 11.3v. This is before the start button is pressed. When the start button is pressed, all you hear is a click. No cranking.

I have had a fiddle with the relays in the car ( what a pig to get to ) and the relays under the bonnet. I added another battery to it with jump leads and it started a couple of times.

I have now put all the covers back and the relays back hoping it was just a loose connection etc, but now it refuses to start etc.

Does anyone have any ideas?

I have read somewhere that if the volts drop, it sense this and cuts out the starter motor relay? But not 100% sure. Does this fault sound familiar to anyone? Joys of French electrics!

I have a code reader, and no codes are showing in any system. ( obd/abs/airbags etc)

Thanks in advance

Renault Laguna - Renault Laguna 1.9 dci starting issues. - hardway

So that's a voltage drop of +1V!

Way too much,

And I'm assuming this is after the glow plug lamp has gone out after the glow cycle yes?

Something is eating up voltage.

'course this being a French car my instinct is high resistance,

So as I see it your going to have learn how to do voltage drop test,

Lots of videos on YouTube.

The most valuable test to learn.

Or call in a spark.

Oh and STOP bying parts!!

You've cost yourself well over £100 so far.

Renault Laguna - Renault Laguna 1.9 dci starting issues. - elekie&a/c doctor

Is this an auto or manual gearbox?

Renault Laguna - Renault Laguna 1.9 dci starting issues. - ScoBro

I did wonder if it was an earth issue possibly.

The battery was knackered due to it being stood and the starter motor was playing up. Very stiff once removed ( 3 hours to get it out )

At one point with two batteries connected it dropped the batteries to 10.5v momentarily.

It's a manual 6 speed

As soon as I put the card in and the glow plug light and all dash lights come on it saps the battery.

Looks like I need to try find out where the power is going.


Renault Laguna - Renault Laguna 1.9 dci starting issues. - hardway

Well your familiar with the starter so it's a place to begin.

Remove the smaller wire to the starter solenoid and connect a fly lead jumper wire.

You'll need enough to run it to the battery.

Now no card,


touch the other end of the fly lead to battery pos+

the starter should engage and spin the engine over but it won't start up.

Diesels need to spin over at least at 180 rpm or higher.

If it doesn't and this test is ONLY testing the power/ground leads from the battery and ground lead to the gearbox further look/see at the connection/wires concerned.

Renault Laguna - Renault Laguna 1.9 dci starting issues. FIXED! - ScoBro

Just for anyone's info incase they have the same issue.

I fixed it. Turned out to be the battery mega fuse had a hairline crack in it. So sometimes when attaching jump leads it would make a connection, other times it would not. £14 and she runs a treat.

Apparently quite common according to the local independent Renault garage.

Well worth a check.

Thanks for the input of others.


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