ZX electrical fault intermittent

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Nick88
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ZX electrical fault intermittent

Post by Nick88 »

Hi there, I have a 1990 ZX Aura 1.9d auto

It has developed an interesting intermittent fault, regardless of distance or weather. So like this morning, traveling the 10miles to work, I get about half mile from work and the batt light appears on the dash (new alternator 6months ago) the lights continue to work, the heater blower and the guages all work along with the engine still driving along. but everything else stops, so wipers front and rear dont work, windows and sunroof don't work and neither do the indicators.. whilst the batt light is on, if you press the brakes the batt light gets brighter and the light for the gear selector gets dimmer... but then after 5 or so minutes of idling, the light goes off and all is back to normal, I suspect this could be an earth strap rather than the alternator? Sorry for the long story. Any advice would be great, I have a Haynes manual too but haven't yet had a look, just wondered if anyone on here has had a similar issue at all.
Last edited by GiveMeABreak on 02 Dec 2020, 10:55, edited 1 time in total.
Reason: Moved to the Citroen Forum

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white exec
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Re: ZX electrical fault intermittent

Post by white exec »

Check out all the grounding points in the engine bay, particulatly those to the inner wings. Unbolt, clean up all contact surfaces back to bare metal, and bolt down again DRY. Only apply a dob of protective grease after bolting down.

Check also the Batt+ main take-off point, a short cable run away from the battery terminal.
Check the small connections to the alternator (there may be two or three): one of these will be the IGN/charging dash light, and if that connection is poor, the alternator output can be erratic.

All points to a bad ground connection somewhere.
If you can post your VIN, we may be able to find a grounding point diagram for the car.

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Pug_XUD_KeenAmateur
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Re: ZX electrical fault intermittent

Post by Pug_XUD_KeenAmateur »

I noted when my Alternator went kaput recently that, in my case, the Battery light failed to illuminate...

I tested it and realised that it'd function fine by either clamping the removed LT lead to the Alternator to Ground

Is there any damage to this wire along its run, allowing it to find a Ground?

On my 405, IIRC, it comes down between the Inner OS wing and the Cam Cover, then under the Injection Pump before terminating at the Alternator. Would imagine if it is finding a Ground, it'd be

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white exec
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Re: ZX electrical fault intermittent

Post by white exec »

The dash alternator (charging/IGN) light works by one end of it (dash end) being connected to IGN+, and the other to a terminal on the alternator, which is at 0v (pretty much Ground) when the alternator is not outputting. As soon as the alternator outputs, the light finds itself with +12 at both ends, and therefore doesn't illuminate.

On old dynamo cars, the light would glow dimly at idle or very low engine revs, as dynamo output was fairly puny at low revs.

There is no harm in grounding the wire mentioned, but don't ground its alternator terminal.
On many alternators, the lamp filament must be intact for the alternator to operate properly; it sometimes has a small resistance across the lamp to provide a working path, should the filament blow.

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Pug_XUD_KeenAmateur
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Re: ZX electrical fault intermittent

Post by Pug_XUD_KeenAmateur »

my apologies to admin if there was a problem with my post, in particular containing lots of line spaces

...I was in the middle of editing said post when my machine acted like the 'Return' was jammed on before it re-booted of its own accord and it'll do nothing more than beep at me now; even an alternative HD won't 'play'; so its probably the MOBO.

Thankfully, all is not lost; I got a new one just a couple of days ago but was planning on running them in tandem for a while, til I've decided whether I can cope with new PC's Linux OS, or if I was to have little choice but to run Win 10.... not a thought I relish!

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myglaren
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Re: ZX electrical fault intermittent

Post by myglaren »

There was a duplicate so one was deleted, otherwise no problem.