Was driving home this evening (approx 10 mins ago) and suddenly all my electrics went off, lights (interior and exterior), radio, air con etc etc. for about half a second then came back on again, only to be greeted by a "service" light on the dash.
Any ideas as to what could have caused this?
Was planning on taking it in for a service in a month or 2 but maybe I should take it in asap?
Any thoughts greatly appreciated.
Scott.
Very Strange Electrical fault!?!?
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myglaren
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Ooops.
Previously:
2009 Honda Civic :(
C5, C5, Xantia, BX, GS, Visa.
R4, R11TXE, R14, R30TX - x 4917
Haven't a clue about the fault. It is recognised that C5 headlights will momentarily blank out occasionally and it is said to be when the suspension pump cuts in.
I'm sceptical about this diagnosis and keep meaning to do some Citroebics in the dark and see the effect on the headlights. Done it in the dusk at traffic lights but couldn't draw any conclusions.
ETA: went out and tested this. No discernible flickering of headlights while the pump is operating! ran the screen heaters, blowers & aircon too.
Don't be too concerned with the "Service" light, it comes on for all sorts of reasons, one being when you run low on washer fluid
I'm sceptical about this diagnosis and keep meaning to do some Citroebics in the dark and see the effect on the headlights. Done it in the dusk at traffic lights but couldn't draw any conclusions.
ETA: went out and tested this. No discernible flickering of headlights while the pump is operating! ran the screen heaters, blowers & aircon too.
Don't be too concerned with the "Service" light, it comes on for all sorts of reasons, one being when you run low on washer fluid
Last edited by myglaren on 02 Mar 2009, 21:52, edited 3 times in total.
Hi,
You don't say what car, but I assume it is a C5?
If correct this is not an uncommon event.
The C5 electronics are very sensitive to battery voltage and if there is a heavy load i.e. lights/wipers/heater fan and the suspension pump also kicks in it can cause the voltage to drop momentarily and trigger ecu reset/glitch.
This is more likely if the battery is getting old >3-4yrs.
Although it may be starting the car fine, the internal resistance of the battery will have increased with time/usage and thus for any current drawn the voltage drop will be greater than when new. It gets to a point where the momentary high current draw takes the voltage below the limit for the electronics.
This is why battery specialist suppliers check out old batteries by checking their ability to sustain a minimum voltage under a known load (i.e. they put a large capacity low value resistor across the terminals and check the voltage.
Also a possibility is that your alternator is on the way out and not delivering sufficient charge to keep battery fully up, but this would also most likely give you starting problems.
Unless you current battery is under three years old I would start with replacing it. Only £50-60 at most motor factors.
Regards
John
You don't say what car, but I assume it is a C5?
If correct this is not an uncommon event.
The C5 electronics are very sensitive to battery voltage and if there is a heavy load i.e. lights/wipers/heater fan and the suspension pump also kicks in it can cause the voltage to drop momentarily and trigger ecu reset/glitch.
This is more likely if the battery is getting old >3-4yrs.
Although it may be starting the car fine, the internal resistance of the battery will have increased with time/usage and thus for any current drawn the voltage drop will be greater than when new. It gets to a point where the momentary high current draw takes the voltage below the limit for the electronics.
This is why battery specialist suppliers check out old batteries by checking their ability to sustain a minimum voltage under a known load (i.e. they put a large capacity low value resistor across the terminals and check the voltage.
Also a possibility is that your alternator is on the way out and not delivering sufficient charge to keep battery fully up, but this would also most likely give you starting problems.
Unless you current battery is under three years old I would start with replacing it. Only £50-60 at most motor factors.
Regards
John
Hi fred,fred1 wrote:Hi,
You don't say what car, but I assume it is a C5?
If correct this is not an uncommon event.
The C5 electronics are very sensitive to battery voltage and if there is a heavy load i.e. lights/wipers/heater fan and the suspension pump also kicks in it can cause the voltage to drop momentarily and trigger ecu reset/glitch.
This is more likely if the battery is getting old >3-4yrs.
Although it may be starting the car fine, the internal resistance of the battery will have increased with time/usage and thus for any current drawn the voltage drop will be greater than when new. It gets to a point where the momentary high current draw takes the voltage below the limit for the electronics.
This is why battery specialist suppliers check out old batteries by checking their ability to sustain a minimum voltage under a known load (i.e. they put a large capacity low value resistor across the terminals and check the voltage.
Also a possibility is that your alternator is on the way out and not delivering sufficient charge to keep battery fully up, but this would also most likely give you starting problems.
Unless you current battery is under three years old I would start with replacing it. Only £50-60 at most motor factors.
Regards
John
Yes it is a C5, sorry probably should of mentioned that!!
The battery is fairly old, I would guess 4yrs + so will change this on weekend.
Thanls for your help.