BSI

[Sol]

Could be either, do you have a DC clamp? Would be good to know what it draws when starting. Would 25A draw, blow a standard 20A fuse, maybe. A bad earth would drop the voltage so less current flows. The cable end voltage = (supply voltage - voltage drop at the bad point), then (cable end voltage / load impedance) = current flowing in the circuit. So a bad earth lowers the load current rather than increasing it.

[jemselectrical]

I don't have a DC clamp meter, only an AC one. My old man said it could be down to dirty commutators in the starter motor. I'm picking up the 25a fuses in a bit once Halfords open, so will see what happens with the correct fuse in

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[jemselectrical]

25a fuse installed, blown straight away

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[Sol]

The commutator in the starter draws hundreds of amps, not the 25A you're dealing with. That's only the solenoid current. The starter on a good day will pull 300A and close to 400A on a cold morning.

I wanted to see if your solenoid was drawing more current than it should do, but I don't think you're kitted up to know this. Most Flukes (mine includes) are only AC but I've a Chauvin-Arnoux too, that does 2000A AC or DC and that's a handy tool.

You should be able to get a DC shunt meter off eBay pretty cheap that would do 30, 50 or even 100A to see what the starter solenoid is pulling but it sounds like it's fooked anyway, BUT make sure the positive terminal on the starter solenoid isn't able to touch any earthed metalwork, or the mesh strap to earth.

That would blow the fuse instantly.

[jemselectrical]

The commutator in the starter draws hundreds of amps, not the 25A you're dealing with. That's only the solenoid current. The starter on a good day will pull 300A and close to 400A on a cold morning.

I wanted to see if your solenoid was drawing more current than it should do, but I don't think you're kitted up to know this. Most Flukes (mine includes) are only AC but I've a Chauvin-Arnoux too, that does 2000A AC or DC and that's a handy tool.

You should be able to get a DC shunt meter off eBay pretty cheap that would do 30, 50 or even 100A to see what the starter is pulling but it sounds like it's fooked anyway, make sure the positive terminal on the starter solenoid isn't able to touch any earthed metalwork.

That would blow the fuse instantly.

Cheers dude, I haven't had much call for a DC clamp meter before, but there's always a new excuse to buy another tool for the armoury

Is it likely to be an issue with the relay that's buried in the engine bay fusebox? I can't seem to find anything on Servicebox that shows where it is, or how to identify/get at it

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[Sol]

That is very possible. F8 and R8 are shown to be the starter circuit control but the relay is never identified in any drawings other than the schematics.

Citroen are really bad for not showing where relays are, never known a make like it for that.

I think there are two in the bottom of the engine bay fusebox, one of those must be R8.

Ok here's a test. 5 pin plug, coloured Yellow on the PSF1 (engine fusebox) then find pin 2 on that plug, that's the feed to the solenoid. See what the impedance is to earth on that pin. For 25A it should be just around 0.5 ohms, if it's less than that by much then the solenoid is drawing too much current.

You need a low ohm device like a loop Z meter (do you have one of those?) - I expect you will if you do EICR for instance. May need to rig up a lead to test this, don't use Megger voltage, just earth loop impedance to that pin with the plug out of the fusebox.

See what it measures. Or do a redneck connection, from that wire direct to the battery+ and see if the starter cranks over direct.

[jemselectrical]

I changed the starter motor yesterday and it's starting on the button every time with no more blown fuse the old one was clearly the original, so not surprising it was hooped. It only took 2 hours and was relatively straightforward compared to the nightmarish DV6                

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[shtu]

Cor, look at all that spaaaaaaace.

I'm not jealous at all.

[jemselectrical]

Cor, look at all that spaaaaaaace.

I'm not jealous at all.

it's like a cavern behind the TU5

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