Flickering lights

[Craigyoung]

Hi all ,
just been away for the weekend and whilst my wife was trying to light the oven with the ignition switch for the flame the kid's bunk bed spotlights were flashing and came on ?! :blink: does anybody else with the same kind of / or any van have this problem or had this problem? Obviously the van is under warranty so it will be sorted but I was just wondering ! a bit eerie hmy:

Craig

 

[Icaru5]

Interesting ...

Haven’t noticed had the bed spots flash Craig, but have had the lights above the upper cupboards flashing when the water pump stops as others have reported.. If they were switched on, maybe the bed spots would also flash too when this happens, not sure. Are you sure it was the oven igniter and not that someone was also demanding water at the same time ?

 

[ProfJohnL]

There have been reports of flashing lights with other Swift vans, I don't know what the outcome or cause is.

 

[Icaru5]

I put it down to a back emf generated when the pump stops,, but was never concerned enough to measure it.

 

[Craigyoung]

Lc ,
I can assure you no one was using the water it was purely just for the oven to be ignited!!

 

[Icaru5]

Lc ,
I can assure you no one was using the water it was purely just for the oven to be ignited!!

Are you sure you didn’t tick the box for the optional Disco Lights pack when you ordered your van Craig ?

 

[Hutch]

Lc ,
I can assure you no one was using the water it was purely just for the oven to be ignited!!

Are you sure you didn’t tick the box for the optional Disco Lights pack when you ordered your van Craig ?

Don't be nasty to Craig, he thinks things through and gets them wrong, .
Sorry Craig can't help. Does it happen when on hookup or just on non site hookup. ?1

 

[Craigyoung]

Ha very good Lc , but with 2 kids , you don't need a disco pack ! Lights turned on and off all the time with them !!

 

[Craigyoung]

Hi Hutch and thanks for the sympathy vote! I am always on hookup when I'm on site and this is the first time it's happened! I will be in touch with the garage on Monday to find out what to do with it

 

[Icaru5]

It does sound very similar to the way the lights above the overhead lockers sometimes flash when the water pump stops Craig, in that a momentary spike applied to the 0V rail of the 12V circuit causes a quick flash from the latest type of LED’s that are fitted to our vans ?

I suppose the only way to prove that theory would be to put a diode inline with the 0V side of the relevant lighting circuit to prevent any back emf from reaching the cathode of the LED, which I know sounds wrong anyway, because an LED is supposed to be just that, a Diode, and so applying a voltage to the cathode should, theoretically have no effect whastsoever, but then again, I’m not up to speed with the latest technologies ...

 

[ProfJohnL]

The majority of LED lights for domestic houses are designed for use with any V supply dc or ac. Consequently a pulse of back emf form a motor, coil or capacitor could cause an LED bulb to flash.

 

[GD485]

I think the problem of flickering or flashing led lights is due to the switches.
My theory is the switch when in the off position acts much like a capacitor. Because LEDs use very low power any rapid pulse can cause capacitive coupling via the open switch to make it flash. On our Coachman the worktop light pulses once when switching off the pump on the control panel.
If my theory is correct then either replace the switch with a item with better air gap or fit a capacitor between +ve and ground just before the switch to dump the incoming pulse and stop it bridging the switch.
Or get the dealer to fix it!

 

[Dustydog]

Craig
Sounds like a poor earth somewhere.

Caravan circuits , unlike most cars need individual earth systems. The weak link is more often than not the earth joints.
They can be hard to detect so as you are under warrant get the dealer to sort it out. Otherwise a weak semi discharged battery may give the same symptoms.

 

[Craigyoung]

DD ,
It's a brand new battery, only been in a week so it's not semi discharged
, its fully charged but like you say it is under warranty and will be ringing them asap.
I will let you all know of the outcome.

Craig

 

[Craigyoung]

.... So I rang the garage this morning where we got to caravan from , explained the situation , they were quick to get a technician on the phone and he explained it is a common occurrence when doing so that the lights will fliker/pulse , nothing to be alarmed about he said , it could also happen to the other ones if they are switched on at the main control but not necessarily switched on at the Light .

 

[otherclive]

.... So I rang the garage this morning where we got to caravan from , explained the situation , they were quick to get a technician on the phone and he explained it is a common occurrence when doing so that the lights will fliker/pulse , nothing to be alarmed about he said , it could also happen to the other ones if they are switched on at the main control but not necessarily switched on at the Light .

Sounds to me as if you got the reply from British Standard "They all do that sir". Mind you many Swifts do seem to. Better take mine to the dealership to see why it doesn't.

 

[ProfJohnL]

This type of problem should not happen FULL STOP. Good design would prevent this. As purchasers contracts are with the seller, they should be telling the sellers this is not acceptable, and the manufacture should be supplying a FOC fix to prevent it.

Swift Take note!

 

[Hutch]

Doesn't happen on our Coachman, Craig, but must admit when in the loo and flushing , don't look at the lights in the lounge. Double check this week.

 

[Dustydog]

Craig
Any spark will,say “something not right Here”.
Take it back ,for resolution now.

 

[Craigyoung]

DD ,
So I rang the other dealer this morning , the other one where we can also take our caravan for warranty work same company different area closer to us & explained the situation to him and he says it should not be happening . He said he is going to contact" Sergeant" I think he said who do the electrical bits , they're going to get back to him and maybe put some kind of "pulsa" I think that's what he said or some kind of little gadget behind the lights to stop it happening , he says when it's getting sparked for the oven theres a little traveling current and there should be something to stop it apparently causing the flicker.

Craig .

EDIT , I meant a "suppressor" behind the lights !!

 

[ProfJohnL]

Sparks (High Tension or HT) ) do not behave like 12Vdc current, and can have some very strange effects, even if there is no obvious direct connection. Sadly sometimes the effects can cause nearby circuits to misbehave and damage sensitive electronics.

Modern circuit designers should be considering not only how to control HT generated by their own circuits but also how to make other circuits immune to the possible effects of HT in nearby circuits.

Products that use HT such as ovens should be designed to make sure the sparks energy is properly grounded and returned to the generator usually through the 0V connections.

About a year ago I did come across a continental caravan where the cooker hob ignitor was not properly earthed, and the return energy relied on the gas pipe connection but it also flashed across to the fridge circuit board damaging it.

 

[GD485]

The Prof is right about high voltages producing strange effects.

An ignitor in a oven may use an inverter or "pump" circuit to raise the 12 volts to a few thousand, This is normally done using a high frequency to make the circuit smaller and more efficient.
However the spark gap will produce radio frequency and might cause an LED to flicker.
This could happen with the piezo electric type ignitor as well.
Personally I think the problem maybe due to pulses some times referred to as "spikes" on the supply wiring, But this is a bit of guess work really like most of the theories that have been supplied on this forum!!

I hope the dealer has some luck sorting it for you. It's really their problem as that's whom you have a contract of sale with (Ref: the Prof John, Sale of goods act multiple posting previously)!

Good like with it.

 

[Leewurf]

Is there anything new to report on this issue? My Quattro FB has the same 'feature' and I know if I take it to the dealer they will insist they don't know / can't find / haven't heard of this problem.

 

[Icaru5]

My van has the same feature. I believe it’s a back emf from the pump motor as it stops rotating. Not remotely concerned, but if I was I’d introduce a diode in series with the pump on the negative side.

 

[Thingy]

There have been reports of flashing lights with other Swift vans, I don't know what the outcome or cause is.

If you recall the post about LED roadlights having problems, this is how it was expalined to me.

The canbus on modern cars sends out a tiny current which is the system testing the various bulbs etc. Not enough to light an incandescant bulb but I am told that LEDs are more sensitive and are picking up this current, hence the flash or flicker. If indeed this is true, and I stress if, then any sort of earth leakage in the caravan could have the same effect and the leds maybe picking that up.

As I said, it was how it was explained to me, whether or not this is correct, I cant honestly say.