heated clothing / 12v power supply / fuse trips?

steveuk

Guest
1200GS. 6 months old 18,000miles.
have been using a heated jacket (with sat. nav, heated grips, autocom system) for a while, running the jacket off the 12v power socket under lefthandside of seat. no problems.

bought the trousers to go with the jacket, they "daisy chain" together - so both use the same power supply. whilst running if i plug the jacket + trousers in the sat nav dies - so does the autocom system........headlights / instrument display are fine.

if i stop running, turn ignition off and on again the sat nav and autocom work again - but the every time i plug the heated jacket + trousers in - the sat nav and autocom "die".

why? they (sat nav and autocom) are hard wired to the battery (unlike the heated jacket+trousers which run off the 12v power adapter). why should overloading the power supply (if that is what's happening) affect the sat nav and autocom?

is the problem as simple as the 12v power supply has too small a rated fuse in it?

will it all be ok if i hard wire the jacket+trousers to battery?


many thanks
 
i can't see why if the autocom and gps are hardwired they should turn off (unless the battery is shot)

are you sure that it is truly hard wired and not powered or switched with a relay or off some other circuity on the bike
 
TUNED IN said:
i can't see why if the autocom and gps are hardwired they should turn off (unless the battery is shot)

are you sure that it is truly hard wired and not powered or switched with a relay or off some other circuity on the bike
Click to expand...

no - i'm not sure that they are truly hard wired - but i am sure the battery is not shot (been on an optimate almost every night since the day i rode it out the showroom)
 
Sounds to me like that when you switch off the ignition you're resetting the current overload devices (fuses on older bikes) and therefore, I'd guess that all of your accessories are wired via the accessory socket = into the canbus.
 
John Armstrong said:
Sounds to me like that when you switch off the ignition you're resetting the current overload devices (fuses on older bikes) and therefore, I'd guess that all of your accessories are wired via the accessory socket = into the canbus.
Click to expand...

thanks.
 
steveuk said:
no - i'm not sure that they are truly hard wired - but i am sure the battery is not shot (been on an optimate almost every night since the day i rode it out the showroom)
Click to expand...

that might help hide a faulty battery.... but i still think you need to check how the gps & autocom are wired.
 
The CANBUS system on the new 1200 series of bikes has no fuses, it simply turns off the affected circuit in the event of an overload or short circuit. You probably knew that much already. If you can find a fuse, it is an aftermarket fit and not OEM.

As other have stated, I would suspect your GPS and Autocom are probably wired off the back of the power socket on the bike rather than the battery, this is the way most dealers tend to wire it to allow the circuit some fault protection and prevent battery drain when switched off. Should be easy enough to check if you lift the seats off. I would suspect that with the heated clothing connected the circuit is shutting everything down for overload protection. Running Autocom, GPS, Grips and heated jacket/trousers may be in excess of the 5 amp rating of the socket wiring.

I had a fault on my R1200GS where the power connector on the back of the power socket had corroded badly and had gone green and almost broken off, leading to intermittent power. This could also be a possibility on your bike.

Hope it is easily fixed.
 
Pukmeister said:
Running Autocom, GPS, Grips and heated jacket/trousers may be in excess of the 5 amp rating of the socket wiring.

QUOTE]

But a heated jacket and trousers running at full chat will take far more than 5 amps. So why isn't the whole lot shut down?

Ley's face it, the Autocom and GPS barelay have any current draw anyway.

And didn't I read that the power socket on the 1200GS is rated at 15 amps, whereas that on the 1150GS is a 5 amp jobbie?
Click to expand...
 
The GS power socket is rated to 10 amps as per news from BMW:

We can confirm that the Canbus aux power socket is ok up to 10 amps then it will stop working until the consumer is unplugged.
We hope this is of assistance to you.
Yours sincerely
Paul Adams
Product Information Advisor
BMW Motorrad UK
Tel: 0800 777 155
Fax: 0870 5050 206
Email: motorrad.information@bmw.co.uk

On the wattage drawn by the clothing, SteveUK didn't say what it was but from a quick look at, say, Widder's elec. clothing site, their clothing ( I guess fairly typical) is maximum: jacket at 48 and strides at 33 = 81 watts. If I have the formula right it's Amps X Volts = Watts, so that's A6.75 X V12 = 81 Watts. 6.75 Amps is well within the CanBus 10 Amp limit. The draw from the nav. equipment is negligable (assuming it's powered by the same CanBus spur as the clothing, which I guess it is as it switches off when - and only when - you plug in the clothing) whilst the heated grips (assuming they are a factory fit) probaly run on an independent CanBus spur, so can probably be left out of the maths.

If I had to guess there is possibly a fault (short) somewhere in the jacket or trousers set up that is causing a draw of more than 10 Amps and shutting down the CanBus. I would start at a check of the aux. power socket, the plug to the clothing lead, the lead and then each piece of clothing and the lead between them. From the info. in the start of SteveUK's thread I suspect it's the trousers or their lead as the cut out only happens when the trousers are plugged in.
 
A couple of us suspect that there's a fault in the latest 1200GS software, that causes the auxiliary power circuit to turn off for no apparent reason. I've seen this happen on my bike with only a GPS connected, or with two BMW heated jackets that worked fine before my bike was upgraded. But then on another occasion, with all the accessories connected, the circuit worked fine for hours.

Do this experiment: Connect all your accessories and wait for the circuit to power off. Then wait 5 minutes and see if it comes on again. The pattern seems to be 3 minutes off, 1 minute on.

If this is the case, my theory is that the control software is at fault, but my dealer hasn't been able to provide a firm answer yet.
 
I would be very surprised if there is an intermittent software fault within the Canbus system itself.

Intermittent faults can usually be traced to a dodgy wire, a corroded connection or, from time to time, a dry joint within the circuitry of the powered item itself. 'Added on' electrical items on a motorbike take a pounding from the weather, salt, vibration, handling and, whilst they may look OK from the outside, are sometimes a bit of a mess on the inside. This is something that Pukmeister found when looking for the cause of his less than 100% reliable power supply. It is quite possible that a broken joint or wire that flexes (joins, breaks, joins, breaks) will, in the small amount of time / gap when the two parts are narrowly apart, draw over amperage as the electricity tries to bridge the gap. The over amperage will then trip the Canbus system (it's only a clever fuse after all) which will then reset itself automatically when the fault (in this case a broken joint / wire) closes itself restoring the circuit. Simarly a straight forward break will cause the Canbus to close down anything else on the same spur, preventing possible further damage.

‘The wrong trousers’ may well prove to be the cause of StevUk’s problems. Have a word with Wallace and Grommit.
 
Why not add an additonal relay, energised from a switched feed (via the igniton switch) to feed all the accessories ?. This relay can then be wired direct to the battery (via an appropriately sized fuse of course). This would do away with all the canbus rubbish.

Ferg
 
Why would you be surprised at a software fault? There have been a couple of widely acknowedged software issues on the 1200 before - for example the "battery going flat" fault that was the reason for the latest software update from BMW. (By the way, just to be pedantic, the CAN bus is simply a bit of wire connecting various control units on the bike together - the (hypothetical) software issue would be in one of these units).

I fully agree that many intermittent faults can be traced to dodgy wiring or the like. But the fault I and others are seeing with the 1200 does not fit this pattern. It's not triggered / corrected by wiggling the wires around, or connecting different devices to the sockets.

However, getting back to the original issue, SteveUk's problem does sound as though his combination of jacket + trousers is triggering the overload protection of the accessory circuit. But I strongly suspect that the latest software from BMW changed the parameters of this circuit (possibly to protect against excess battery drain - after all that was the point of the software changes), and that they got it wrong in some way, causing spurious triggering of the protection.

My recommendation to Steve would be to continue to run the autocom and GPS from the accessory circuit, and add another socket for the heated clothing, that is wired directly to the battery via a 10A (or maybe 15A) fuse. I've currently got my underseat socket wired to the battery so at least I can have heat when the bike's computer is having its little temper tantrums :)
 
Wapping said:
..... jacket at 48 and strides at 33 = 81 watts. If I have the formula right it's Amps X Volts = Watts, so that's A6.75 X V12 = 81 Watts. 6.75 Amps is well within the CanBus 10 Amp limit.
Click to expand...

Agreed on the calculation.

But I wonder if heated thingummywhotsits take an initial load which is higher than the steady state?

With regard to satnav etc, I'd agree that they've been wired in either directly off the back of the acc socket, or powered viua a relay trigged by the acc socket.

As mentioned above, I'd bypass Mr Canbus and his overloads by triggering a relay off the ignition circuit to power up all the add-ons. Jumper onto the blue/green wire at the diagnostic plug for the trigger. There's a good explanation on this in www.r1200gs.info
 
ferguscawley said:
Why not add an additonal relay, energised from a switched feed (via the igniton switch) to feed all the accessories ?. This relay can then be wired direct to the battery (via an appropriately sized fuse of course). This would do away with all the canbus rubbish.

Ferg
Click to expand...

This is good advice :thumb but only if the recipient has the confidence / ability to carry out the work :eek:

I suspect (no offence intended if I am wrong) that SteveUK may not be 100% on electrical matters. For instance, he was worried about a fuse in non-fused system and was unsure whether the navigation gear was wired direct to the battery, or how much power he might be drawing. Unfortunately, your otherwise good idea, would not help if the trousers (as would seem likely) are the offending article, the separate in-line fuse would simply keep blowing. My real impression of SteveUK’s appeal for help is that he is looking for a possible complex reason (a fault within the Canbus system) before exhausting a much simpler posible cause….dodgy trousers!

Touratech make some pretty simple fused blocks that can be used to tap power direct from the battery and would save the trouble of splicing in wires, difficult enough on a Canbus if you are not 100% confident what you are doing. As they sense the key in the ignition switch they automaticaly power-off, thus avoiding a flat battery. Look for TPS 15 for BMW R 1200 GS 15A relais (sic) switch and SSR-01 voltage control module BMW R 1200 GS on Touratech's website. These are separately fused, as they would need to be if running directly from the battery, and carry sufficient ampage for 99% of day-to-day needs.

Canbus is OK as a system and is appearing more and more in cars and bikes. It saves weight, is easy to install on the production line and actually makes adding additional items quite easy for less confident owners, via ‘Plug-and-Go’ into an auxiliary socket. One only has to look at the mass of items wired directly to batteries on many conventional ‘simpler’ fused motorbikes to see that many people are not confident about cutting wires or suspect that something complex has gone wrong when the real answer is much simpler.

Richard
 
jedi-knight said:
But I wonder if heated thingummywhotsits take an initial load which is higher than the steady state?
Click to expand...

I agree it's possible but it's one big draw from cold. Say 121 watts to give 10+ amps. Seem unlikely? :nenau The Widder figures I quoted were maximums, by which I read 'From cold' but could be wrong :nenau

SteveUk could possibly check by monitoring at what point the Canbus failed to safety but the result might be upset if it's the simply dodgy trousers.

Either way, it would be nice to hear what the final answer was.
 
My daughter tells me most of my trouers are dodgy. Can't see her point. 1970's flared jeans with bits of fur will come back into fashion. Eventually.

Back on topic, it will be interesting to know the outcome.
 
Wapping said:
I agree it's possible but it's one big draw from cold. Say 121 watts to give 10+ amps. Seem unlikely? :nenau The Widder figures I quoted were maximums, by which I read 'From cold' but could be wrong :nenau

SteveUk could possibly check by monitoring at what point the Canbus failed to safety but the result might be upset if it's the simply dodgy trousers.

Either way, it would be nice to hear what the final answer was.
Click to expand...

In the case of a heating element, yes it is possible to have a larger current draw when cold. The resistance of the heating element (wire) increases as it's temperature increases. As the resistance increases, then the current it draws decreases. (Voltage = Current x Resistance. Voltage is constant @ 12v)
I can only assume that the wattage stated by Widder relates to the jacket / trousers in 'heated' condition.
Therefore, for the first few seconds after switching on, there is a possibility that the clothing may draw more than the 6'ish amps stated.

Ferg
 
ferguscawley said:
In the case of a heating element, yes it is possible to have a larger current draw when cold. The resistance of the heating element (wire) increases as it's temperature increases. As the resistance increases, then the current it draws decreases. (Voltage = Current x Resistance. Voltage is constant @ 12v)
I can only assume that the wattage stated by Widder relates to the jacket / trousers in 'heated' condition.
Therefore, for the first few seconds after switching on, there is a possibility that the clothing may draw more than the 6'ish amps stated.

Ferg
Click to expand...

Agreed, V=IR. It was the size of the rise that surprised me, hence my :nenau
 
am going to try wiring the jacket + trousers direct to the battery - will let you know if this cures the problem....

it looks as if both the autocom and sat nav are wired off the rear of the 12v powers socket under lefthandside of seat - both power down after 15 / 20 seconds after turning the ignition off.

it occurs to me it wouldn't be a problem to "hard wire" the heated clothing to the battery cause i am obviously gonna leave the bike (and dissconnect the clothing) when i turn the ignition off so battery drain won't be a problem...

thanks for all your comments so far...
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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