Random Hazards

[ScottR400D]

Went for a blat this afternoon, about an hour, 40 miles or so. About 2 miles from home hazards started flashing. Proceeded to go on and off randomly till back in garage. 

Seemed to stop coming on on their own after being stopped for a while but though they switched on and off thereafter, when turning off the gauge needles would rotate as they do when turning ignition in and off. Perhaps thats normal?

Anyone had hazards with a mind of their own?

2015 R400D. All round push button switches  

 

 

 

 

 

 

[Jonathan Kay]

Anyone had hazards with a mind of their own?

Conventional response is to cycle the hazard warning light switch and the indicators a few times. But I don't know if that known problem affects all types of switch.

... when turning off the gauge needles would rotate as they do when turning ignition in and off. Perhaps thats normal?

I don't understand what you're describing in that bit...

Jonathan

[ScottR400D]

Hi Jonathan, thanks for the quick response. 

So you think the issue would be with the switch? It just seems odd that it would just start to do this randomly. This is my main concern, it's worrying that the hazards can just turn themselves on randomly.

As for the other I'll try to clarify. I have no ignition key, I just put the transponder near the sensor and then press the button which turns on the ignition. As I do that all of the gauge needles sweep over the dials and then go back to rest. 

Pushing and holding the button starts the car. Pushing and releasing turns it off and turns off the ignition. 

What I noticed is that, with the ignition off, pressing the hazard switch turns on the hazards, as you would expect. Pressing the switch to turn them off switches them off but as you do that, the gauge needles all make a sweep, as they do when the ignition is turned on. Perhaps this is normal?

Hope that's a bit clearer?

[Jonathan Kay]

Yes, the problem that has been observed several times sounds like faulty contacts that clean up after being used. I don't know how long they last after that trick has worked, but I don't think I've heard of any failures.

Does anyone know precisely what causes the gauges to sweep on that type of dash? Or can anyone replicate the effect of turning off the hazard warning light switch?

I'd start by watching the battery voltage as you do it.

The other thought is that it might be worth finding out where the relevant relay lives while we're waiting for the experts.

Jonathan

PS: Do you have a wiring diagram already? And a multimeter? :-)

[ScottR400D]

Also notice that all of the dials, speed,revs, fuel, water and oil, fog up a little when it's cold outside. I'm running the heater all the time, which is pumping a lot of warm and probably quite moist, air up behind the scuttle and dash. 

I wonder if this could be the root of the hazards issue?

[SM25T]

Shouldn't be. Misting gauges is common. I would try pressing all relays fully home. They can shake loose. The hazard switch problem was related to the old 1980s rocker switch.

[ScottR400D]

OK. 

Yes, I have a multimeter and diagram. The relays appear tpo be on a panel just above the heater panel under the scuttle. Haven't had a close look at them yet.

 

 

[SM25T]

Just push them all home

[slap_ed]

Just for information....

Same car and it sounds the same dash. Mine does the same as yours in that all the dial will sweep fully round and then settle back on zero or at the temperature if the engine is hot. 

What is strange on mine is that when the ignition is off and you press the button for the side lights, the gauges sweep fully and just stop and leave the needles pointing high on all of the gauges. They will stay there indefinitely until you put the ignition on where they'll sweep fully and then settle back to zero.

If anyone can explain why this happens and whether this need fixing or not?

My hazards haven't been a problem but I'll give the switch a wiggle next time I'm in the garage.

[aerobod - near CYYC]

slap_ed, my R400D also has a variable sweep that sometimes leaves the needles not at zero when power is switched off. I don't think there is an issue, just seems to be how much momentary power is applied to the instruments and whether they manage to complete a full test sweep before the power is removed.

ScottR400D, In terms of the hazard lights not working, if it is not the relay, it could be the switch element itself. The R400D switches are both a work of precision engineering and a nightmare all at the same time. They are completely modular, expensive and finely engineered. The button, bezel, mounting and switch element are all separate and are from the EAO 61-series of switches. (Here is the relevant catalog from EAO, the switch element start on p651! http://eao.com/fileadmin/documents/PDFs/en/01_main-catalogue/EAO_MC_61_Main-Catalogue_EN.pdf). If the switch element has gone bad, you either need the special removal tool or 2 medium sized tie-wraps to insert into the 2 rectangular slot on the back of the switch, you then press into the slots to pop the switch element off. I had to do this to replace my "start" switch button, that is when I appreciated both the elegance and nightmare these switches present! In the UK Farnell is probably the best source of parts for this switch, if you have to take it off, you can examine the switch element and determine which part number it is for replacement.

[ScottR400D]

Just been to check and,with ign off, if you turn lights on the dials part sweep. Switching off they move some more; if you hold the switch as the lights go off they will sweep all way round then back to base.   

Didn't switch ignition on so not sure what they'd do but guess they'd be as you described. 

Seems this dial sweep with seemingly disconnected functions may be normal. Did you check what they do when you turn hazards on and off, with ign off slap ed?

[ScottR400D]

Thanks Aerobod, that makes sense. 

One thing, what type of failure, of either the switch or the relay, would cause the hazards to come on randomly?

 

[aerobod - near CYYC]

I would say a loose contact or broken spring would be the most likely cause.

[ScottR400D]

On the switch? But how would a loose relay cause them to come on?

[aerobod - near CYYC]

I would say inside the switch or relay there could be a broken component, also worth checking there is no short or touching spade connections between the wiring on the back of the switch. It looks as though 2 relays are involved with the hazards / indicators, as shown on the wiring diagram, by correlating the connection numbers:

[Jonathan Kay]

While you're waiting for the new switch... is there any residual problem or is it all fine now?

Jonathan

[ScottR400D]

Hi JK. It seems OK at the moment, though I haven't had the car out on the road. All behaving perfectly in the garage.

Once I have the spare switch, I'll give it a run and see if it does it again, then change the switch if it does.

 

 

[Jonathan Kay]

Got it, and that sounds pragmatic.

I'll put my money on non-recurrence.

:-)

Jonathan

[ScottR400D]

Hi all.

Well, I got a new push button switch from Caterham but haven't yet fitted it. As I reported earlier, It was all behaving as expected in the garage.

However, I just came home from a few weeks away and pressed the hazard switch. They all started flashing but wouldn't stop. Disconnected the battery and they stop, of course; reconnect the battery and they stay off but they start againon the switch and again won't stop on the switch. Battery disconnected again.

Now that seems to indicate, possibly, that the switch is faulty and isn't working when its pressed to turn off. Of course any other component in the circuit could be giving the same symptoms but at least I now have a repeatable symptom so I plan to swap the push button that Caterham sent me.

Caterham tell me that the switching element simply pulls off the back of the push button, no special tool is needed. I infer that the 'switch element dismantling tool' available from EAO is for dismantling the switch element further once it's off the push button.

Can anyone confirm this is correct or otherwise?

As, it seems to me, the fault is just as likely to be with the switch element itself, I think I'll buy one of those and the little tool kit too so at least I'll be ready to change that part if the the replacement of the push mechanism doesn't work.

I attach an image of the actual switch from the rear. It's the left one with 2 purple, 1 black and 1 green wire. The blue bit is the switch element. Its actually the upper switch in the image but for some reason uploading it rotates the image left 90.

 

 

[Jonathan Kay]

If that swap doesn't solve it I'd want to:

1. Be able to study continuity through the switch as it's operated.
2. Check those relay(s).

Can you operate that switch in circuit with it exposed to give easy access to the terminals?

Jonathan

[ScottR400D]

I think I know what you mean. I can't do that in situ but can if I remove the switch. But doing that might disturb the switch element and name it seem OK. seems a very complicated mechanism for such a simple job. Form over function? 

May main concern at the moment is how I get the blue but off the rest of the switch. 

Thank for your quick response as usual JK! 

[aerobod - near CYYC]

I looked at pulling the switch element off the back of my start push button, but it is a bit risky that the locking tabs that hold the push button to the switch element could break instead of releasing. Two largish zip ties with the tips cut off were a good fit into the rectangular holes in the back of the switch element, just push them in to ease the locking tabs open and allow the switch element to be pulled off the push button with little force.

[ScottR400D]

Thanks Aerobod. So you're saying that the tool is definitely for separating the switch element from the push button and not for dismantling the switch element itself, as I was led to believe. I think you're right. 

I'll wait until I have a whole new assembly before I change the switch, that way I can fully understand how it all works before I remove the old one. 

[ScottR400D]

Right. Changed the whole switch and you do need the little tool, or a couple of small cable ties but the tool is better, to separate the switch element from the push button. 

Didn't make any difference so, as I'd already change the flasher unit, I contacted CC and they sent me a new pcb. I plugged that in temporarily and all seemed fine after a couple of runs out so I fitted it properly this afternoon.

Seems the whole system works with the switch, flasher unit and 3 latching relays on the pcb, one of which has been failing intermittently.

Odd thing is that you have to remove the heater to get at the crews that pass through the bulkhead and into captive nuts on the pcb plate. Makes it a much longer job than it could be. When I have a bit of time I'm going to change the arrangement and make it removable from inside the car.

[ScottR400D]

Just to finish this off, if anyone's interested, the replacement pcb, which solved the problem but suffered some cosmetic damage in shipping, was replaced again by CC.

I fitted it on anti-vibration mounts, instead of it being fixed solidly to the bulkhead, so hopefully it will now be more resistant to road shocks. It now has the added advantage of being quickly removable from inside the car, as opposed to having to move the heater.

Credit to CC, the response once the failure happened has been excellent, plenty of advice and replacement parts shipped overnight each time.