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odd electrical problem

Feb 23, 2010
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I have a 1.4 Astra Estate Merit, P reg - 1996

About 3 yrs ago, soon after I bought the car the engine management light came on at various times throughout a journey, sometimes staying on until the car was switched off. I did the paper clip test and it gave an idler control valve fault. I replaced the valve with a new one, but still the EM light would still come on [intermittently]. I've lived with it ever since!

Last week, the hazard lights stopped working [meaning, when the switch as pressed the green indicator light on the dash board came on continuously without flashing, but not the actual lights]. Oddly, if the side lights are also on, not only does the green light stay on, but the flasher relay buzzes too. I've replaced the relay with both an old one and a new one, and also tried another hazard switch] but still the problem remains.

Nextdoor neighbour is a mecahnic and tried to read the engine management with two different readers, but the car doesn't seem to be activating the readers [one was a laptop with some software doing all Vauxhall cars and the other was a device from Snap-on, with various keys etc]. Both devices had this model and year listed, but nothing happened on both occasions.

Strange too, is the fact that I've lost power to the radio and also the clock and temp gauge [just above the radio], which is strange.

It's hardly worth a lot to warrent spending much on it, but not having the hazard lights is concerning, I use them quite a bit to reverse into a tight driveway. I'd really like to get these sorted.

I've had a look at the fuses and they all seem ok.

This is an odd car.

Any ideas anybody?

Many thanks.
Sounds more like a fuse issue, i'm sure one fuse controls all or most of what has stopped working?
I blew the hazard flashers, check control and horn fuse when paper clipping my old Cav CDX X20XEV...

Go to pound land (Maplin etc) get a bunch of fuses and play. You'll find they'll most likely come back on when you replace fuse by fuse. Remember, they sometimes don't look blown when they have gone.

Narrow it down, someone on here posted up all the fuse locations a while back, take a look about and see what's going on. Probably really simple.

will check again

I have some time tomorrow, I'll double check the fuses again. I'd be interested to know the location of that fuse diagram.
Thanks for replying.
1. Central locking [20 amp] (*)
2. Fuel pump [20 amp]
3. Windscreen Wipers [30 amp]
4. Dipped beam - left [10 amp]
5. Dipped beam - right, headlamp range adjustment (*) [10 amp]
6. ABS (*) Automatic transmission (*) [10 amp]
7. Electric/ heated mirrors (*) electric sunroof (*), control indicators, swich symbol lights, fuel + temp guages, glove box + boot light, information display, clock [10 amp]
8. Terminal 30 constant current for caravan/ trailer. [20 amp]
9. Headlamp warning device, daytime driving lights (*), information display
10. Electric windows (*) electric roof (cabriolet) [30 amp]
11. Fog tail lamp [10 amp]
12. Main beam- left [10 amp]
13. Main beam - right [10 amp]
14. Heater fan, air conditioning system [30 amp]
15. Cooling fan [30 amp] Cooling fan turbo Diesel engine [40]
16. Heated rear window. [30 amp]
17. Front fog lamps (*) [20 amp]
18. Parking and tail lamps {left} [10 amp]
19. Parking and tail lamps {right}, instrument illumination, number plate light, radio (*) [10 amp]
20. Reverse lights, cigarette lighter, heated front seats (*) [20 amp]
21. Cooling fan - air conditioning system [30 amp]
22. Electric windows, window closing safety system (*) [30 amp]
23. Headlamp wash system [30 amp]
24. Courtesy light, boot light, hazard warning lights, horn, clock, radio (*) trip computer (*) [20 amp]
25. Automatic transmission (*) [10 amp]
26. Cooling fan - turbo Diesel engine
27. Daytime driving lights (*) [10 amp]
28. Turn signal lamps, hazard warning, brake lights, ABS (*) [15 amp]

at the rear of the fuse box;

Anti theft alarm system (*), horn [10 amp]
Electric roof - cabriolet (*) [30 amp]

As above (*) represents option equipment.

Hope this helps,


Many thanks!
I'll report back if get anywhere tomorrow.
I had something very similiar on a corsa b once. Turned out it was 2 fuses that had blown, hence the reason why none of the things were working. As above though, check the fuses for damage.
Hope you get it sorted mate.

Remember, they sometimes don't look blown when they have gone.

The moral of the tale is: when you check a fuse, look very closely grasshopper because they sometimes don't look blown when they have gone!

I'd forgive myself if it was the first car I'd ever worked on, but....never mind.

What was interesting was that particular fuse [No24] was also affecting the lack of engine management reading, I've now got a reading from my neighbour's diagnostic device.

Thanks again for the help.

I come to you again oh wise ones....

.....OK, I ascertain it's the fuse and replace it, but over the course of the preceeding month, the fuswe continues to blow. And so I replace it.

Fuses blow for a reason right? Pretty obvious. But I couldn't really work out anything on thisd circuit that was blowing it.

Recently the horn has packed up completely. I take the front grill off and run a couple of leads to the horn from the battery, and it seems fine.

Sitting in the cart trying to suss this out, this fuse goes again and this time I smell burning....and see smoke in the mirror! Bloody hell it's on fire! Well not quite, but it almost could have been. So I immediately switch off the ignition, go to the back, see smoke pouring out of the courtesy light hole [I say 'hole', as in there was a gap where the broken light had been removed] rip the ceiling mat away pull the [very hot] wires out and find 4 exposed wires with no rubber surrounds! The two wires from the light had been dangling down [silly me], and gradually frayed against the metal chasis and obviously been causing the shorting problem all along. The aerial cables[there are two, coaxial and another black (with white stripe) wire] had also had their outer sheathing burnt back to the bare inner copper wire. Dear oh dear, what a mess.

So. I replaced about a metre of the aerial wires [radio seems to work ok] and traced the light wires as far back as I could until I got to what resembled proper looking wires again [just before the rear wheel arch], and just capped them off. But the two light wires are puzzling - there's a red and brown [with a white stripe]. The red is live [tested with a bulb tester], but the brown seemed to be dead, should there not be a continuity to earth with this wire? Surely two wires going to the light are live and earth? I can't figure out where the earth is switched though. With the rear doors open I still get nothing. Bit confused about that wire. The red live if going back towards the engine, but the brown/white wire goes into a block which them heads up to the heated rear window.

Problem I've now created for myself is this: when I turn the ignition on, no lights on the dash at all, it's completely dead, and yet the car starts fine. But after it's started, the charging light comnes on. Oh s*** I've blown the alternator. Jumping to conclusions, I fit a new alternator and got exactly the same. Got a multimeter and there's plenty of charge going to the battery. But no lights on the dash at all. But the indicator lights work, as does the blue full beam light. Very faintly, it looks like you can just see the handbrake light come on and off as you use the hand brake.

And the horn isn't working - remember that wasn't working before the 'fire', although those cables have been burning themselves out for a while I'd have thought. I've head a look at the horn and the two wires going down to the horn are red and a brown with white stripe. The red is live [tested that with a MM] and the brown/white a switched earth?

All the fuses are fine. I've tested all those with a MM [with ignition off].

Does this sound like an earthing problem? If so, where on 'earth' is the problem?

Or is there other, unseen, damage done by those burnt wires? [Even though I traced the wires back to good cable].

Any suggestions appreciated. Ta.
the horn could be the squib wire in the steering wheel there common to go faulty on the vauxhalls.and the wires you was on about could be a switched earth where when you open the tailgate etc the light will come on. so that could be why that wire is dead when its shut. hope this helps

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