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Battery Overheat and Electrical Fault on '05 ST.

7K views 35 replies 8 participants last post by  Tone5 
#1 ·
Looking for some advice please with tracing an electrical fault on my '05 ST 1050?

While stopped for a coffee on a hot day (after riding about 70 miles) I noticed a humming sound from below the seat (without the engine running). Soon thereafter, back on the road, I was aware of lots of heat under the seat, and then all the instrument panel lights came on for a second before everything went dead.

I pulled over and found steam-like gas coming from under the seat and the humming sound again. I removed the seat and found the battery was very hot.

Breakdown assistance returned me home and since then I have been trying to work out what's gone wrong.

3 fuses were blown: 15A fuse for fan, 10A fuse for ignition and the 10A fuse which has an ‘alarm’ symbol (fuse number 9) on the underside of the fuse box lid.

I took the battery in to be tested. It was found to kaput and was replaced under warranty (it was only a few months old). The guy at the battery shop says that if it had been over-charged he would have expected to see some heat stress/swelling of the battery case.

With the new battery fitted and the fuses replaced, fuse number 9 blows as soon as I reconnect the battery, even with the ignition off.

I replaced the regulator rectifier a few thousand miles ago. It is not an OEM part or a Mosfett type. I normally keep the battery topped up with a 300mA trickle charger for 3 hours per day (using a timer plug).

I realise that I'm probably going to have to get lots of plastics off and start inspecting wires and connectors for shorts/poor contacts. But before I start this major surgery, does anyone have any tips to offer?
Thanks
 
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#2 ·
Assuming it works with the #9 fuse out, the first thing to do is to run through the tests here. If it doesn't work without that fuse, the first thing to do is to replace the alarm with a blanking plug and then run through those tests.

Cheers,
-Kit
 
#3 ·
Tone5 - I have experienced exactly the same situation. Replaced the R/R a couple of months ago. A few thousand km's later and my battery and bike exhibited the same symptoms as yours. At the moment I haven't completely gotten my bike home. I'll keep you posted on anything I find out.

Fitz
 
#4 ·
I have a story to tell that may shed some light on your issue.
I noticed that in the morning the battery was sluggish and after a few days and a cold morning would not start the bike. I assumed the battery was dead and replaced it. A week later the new battery did the same. so I hooked up a volt meter and sat it on the dash. every thing normal 13.5volt charge. but, when the bike warms up after 10 mins the voltage then starts to decline. I watch it go from 13.5 to 12.5 to 12 to 11.5 after 30 mins. So I assumed the reg rec was toast and replaced it.

Went on a longer ride and found that the voltage was good for an hour then went 13.5 to 13.8 to 14.5 to 15 to 18volts. Then my lights blew out. pulled over to buy more bulbs and started up again. volts 13.5 to 12 to 11 to 10.5 and stop.

I pulled out the stator and it was cooked and crispy on one phase.

It appears that ongoing reg rec issues and overcharging are probably due to a stator that is on the way out. Only faults initially at high temperatures. if the fault is half way along windings then I assume either high voltage or high amps would be the result. Thus cooking the reg rec and the battery.

My stator was checked for earth leakage and volts (it did read a bit lower than I expected) and looked ok prior to this so it is not easy to diagnose a bad reg rec. Pull off the side cover and check for signs of overheating and charging on one of the phases. If it shows discolouration then change the reg rec. Ricks USA supply after market.

Warning whinge below;
The shops in Aus no longer carry reg recs on the shelf and can order one in in two days. didn't even ask about the stator cause the fact that they don't have reg recs pissed me off too much. Ordered all online from USA. I expected the shops to carry spare parts and not wait for me to come in before ordering them. I can order items and have them posted directly to my house and have them there in two days. Why would I bother having the shop do that and then I have to drive back to the shop to pick it up. Idiots...
 
#5 ·
Oh on another note it is possible to ride the bike with the reg rec and stator disconnected. I pulled out the headlight connector and rode over 100km home this way. A full battery is needed though. got about 10km per 0.1volt drop in battery charge. Made it to 10.3 volts before she stopped. so from 13.3 volts to 10.3 volts is in theory 200km. Remember this next time the reg rec gives up the ghost.
 
#6 ·
If the stator windings are reduced because of a short then the voltage out put will be reduced. Not sure if this then equates to an increase in amps. At higher revs where volts would be 60volts and 30 amps could it be that the volts goes to 30 volts (therefore still looks like it is charging) but 60 amps. This would over charge the battery or cook the reg rec, or both.

It is recommended to do the ohms and volts test on the stator at operating temperatures. as a hot coil could give different results to a cold test.
 
#7 ·
Tone - I found three fuses to be blown. I think it was the same ones as yours. Replaced all blown fuses and connected a battery booster pack to the battery leads. With the ignition key turned off, Fuse #9 blew...twice. Apparently, this fuse controls the instruments and diagnostics (and alarm?).

I stripped all the plastics off to reveal the instrument panel wiring harness to look for a "smoking gun". Nothing smoking...

Note that the regulator/rectifier was disconnected from the battery (but not the stator) when I powered the bike.

Tomorrow, I will disconnect everything I can find running to the instruments and try powering up the bike again. I'll start reconnecting until the fuse blows. I'm thinking the ECU has been "zorched" ($$$).

Also tomorrow, the mechanics (ski hill vehicle maintenance shop*) will be back at work, so I can pick their brains.

Stay tuned.

*Yes, I work at a ski mountain resort. My job is better than your vacation.
 
#8 ·
A stator puts out ~20-100 or more VAC per phase. If you're seeing 18 VDC at the battery, your regulator is shot. You also can't tell a bad stator from a good one by looking; the top part has looked cooked every time I've pulled that cover, regardless of whether it was good or not. The distance you can go without charging is also highly variable. I blew my main fuse last week and went from ~13.7 to 10.8 in six or seven miles. I don't mean to pick on you, Bad Billy, I just don't want people replacing the wrong parts or thinking they can go longer on battery than they can.

Cheers,
-Kit
 
#9 ·
Thanks all for your replies and the great information, which I'll digest and plot a course of action.
Kit, thanks for the link to 'the charging system diagnostics page' - great info. What exactly do you mean by "replace the alarm with a blanking plug"? Do you mean creating a short across the terminals of fuse 9 with a piece of wire? Wouldn't this risk damaging other parts of the electrical system? By the way the bike's previous owner removed the alarm.
Fitz, your bike's symptoms are indeed very similar to mine. I look forward to hearing what you discover, unless it's a zorched ECU.
Cheers
 
#11 ·
Tone5 said:
<...>Kit, thanks for the link to 'the charging system diagnostics page' - great info. What exactly do you mean by "replace the alarm with a blanking plug"? Do you mean creating a short across the terminals of fuse 9 with a piece of wire? Wouldn't this risk damaging other parts of the electrical system? By the way the bike's previous owner removed the alarm.<...>
I absolutely DO NOT mean short out the fuse! There is a connector in the harness that the alarm plugs into. If the alarm is not installed, a blanking plug must be installed in the alarm connector or the bike will not run. If the bike ran without the alarm installed, the blanking plug is there. (Might be worth inspecting, though, since that fuse is blowing.)

Cheers,
-Kit
 
#12 ·
Tone

I disconnected everything that I could find, including the ECU and the Instrument Cluster.

Fuses blew when the ECU and the Instrument Cluster were reconnected. So, my conclusion is that those components experienced excessive voltage and fried.

Further, all headlight bulb filaments were blown and/or melted, including the "Euro" bulb. This was the third fuse blowing.

I removed the instrument cluster and disassembled. It definitely had a "the smoke escaped" type of smell. The ECU is a sealed unit, so no way to tell if the smoke is still in there.

At this point, a new ECU on Bike Bandit is $1770 (USD) so probably over $2000 for me (Canadian). I haven't priced a new instrument cluster.

Either I source used parts (there's a wrecked bike in my province) or I part mine out. Given it's value, I'm ready to stop the madness and get rid of it.

Also, I still haven't figured out the reason for the overcharge. Probably a faulty R/R.
 
#13 ·
Greetings all
Here's my latest update. I've spent some quality time with my multimeter in the shed looking for the cause of my bike's issues.
I've done the R/R and stator checks as described here http://www.triumphrat.net/speed-triple-forum/104504-charging-system-diagnostics-rectifier-regulator-upgrade.html
This has not revealed any faults.
I have removed the earth terminal, wire brushed and cleaned the contacts. There is very low resistance (about 0.2 ohms) between the battery's negative terminal and the earth terminal and the cables connected to the terminal are in good condition.
I have removed the instrument cluster and opened it. It all looks clean and new inside. Visually I cannot see anything wrong in there.
I have tried disconnecting the R/R, instrument cluster, ECU and many other components and the problem remains. The problem is that it blows fuses numbers 8 (engine), 9 (alarm) and 2 (ignition) as soon as I turn on the ignition key.
I have disconnected the battery and measured the resistance between the positive battery lead and the bike's earth terminal (in other words the resistance that the battery sees). I get 276k ohms when the ignition switch is off. When I turn the ignition switch on this resistance drops to 6k ohms.
Because the battery is blowing fuses it must be supplying lots of current as soon as the ignition is switched on (the engine fuse is 20A) and therefore I was expecting to see a low resistance. However the resistance I measure is 6000 ohms, which means that the current drawn should be 0.002A.
I=V/R, where V=12V and R=6000, therefore I=0.002A
Clearly a lot more than 2mA is being drawn from the battery. Can anyone explain this or show where my reasoning is wrong? Alternatively can anyone suggest any other things I should test to establish what the fault is.
 
#14 ·
Unplug your headlights. They come on when you turn on the ignition. There are three lights, the two low beams, the high beam, and the mini bulb in the high beam pod. AND, unplug the ECU and Instrument cluster. My headlight bulbs were not merely blown but the filaments were, well, welded.

Probably doesn't matter but to rule out your battery, disconnect your battery and connect a booster pack (a portable battery for boosting dead cars).

Replace the fuses. Connect the booster pack. Turn the ignition on. Observe the fuses (takes a second person). Reconnect the ECU and then the Instruments.

Then push it off a cliff and buy a Multistrada.
 
#15 ·
Your reg/rectifier has a dead short to earth. Anotner clue is your first post where you said your battey was hot ( obviously overcharged). Borrow another reg from somewhere, non Triumph item will work and confirm my theory or otherwise. Also email the guru Mr Decosse for his expert advice. Keep us posted pls.
 
#16 ·
Thanks for continuing to follow this. I still have not found the 'smoking gun'.
Adrian1, I'm certain that there is not a dead short through the R/R. It blows fuses with both plugs of the R/R disconnected from the rest of the wiring loom.
Fitz, I've done as you suggest. I disconnected all headlights (all the bulbs were blown), ECU and instrument cluster. Then I replaced the blown fuses. As soon as I turn the ignition switch to the on position it blows the fuses again (good thing I bought lots of spares). This was done with the R/R disconnected at both plugs. I'd be surprised if the cause were the battery because the battery is brand new. The voltage across the terminals is 12.8V.
The problem and the solution are there, I've just got to find them.
 
#18 ·
Thanks for the suggestion Pcdabbler. The O2 sensor looks fine and all the symptoms remain when I disconnect it.
Yesterday evening I blew something in the instrument cluster (what a plonker I am!!). I connected a multimeter across the fuse terminals with the meter set to measure current. The meter read 14A then something went pop in the instrument cluster. Now it looks like I'll need to find a replacement instrument cluster before continuing to search for the fault.
I guess I've got what I deserve for being careless.
 
#20 ·
Armed with a multimeter and circuit diagram I've started checking the wiring loom and I reckon I've found the fault. Finally some progress!!
There's a brown and pink wire that goes from the EMS relay to the ECU (pin A6), with branches off to the fuel injectors and the 02 sensor. There is continuity between this wire and the bike's frame. The continuity remains until I disconnect the plug which fits to the ECU.
I think that this is telling me that there is a short to the bike's frame through the ECU. I've checked the other arms of this circuit (which go to the cooling fan relay, neutral switch and the engine starter switch) and not found any earth leaks there. I intend doing further checks on as much of the wiring as possible to see if there are any other faults.
So, it looks like I have a faulty ECU. Does this diagnosis sound plausible? Are there any checks I can do on the ECU to test it? How do I tell if a particular second hand ECU will work with my bike?
Will the bike run without the instrument cluster? I blew something in the instrument cluster last week, so probably have to replace that as well.
Thanks
 
#22 ·
Thanks Adrian1 for that link. I've removed, cleaned and tested the relays. They were slightly dirty due to dust collecting in the grease which the previous owner must have applied to the contact pins, however they're all in good condition and work as they should. The problems remain after I cleaned them.
I also checked the kill switch (again). Inside it's clean and there are no shorts between the terminals or from either terminal to the frame.
I'm still convinced the leak to earth is through the ECU. One of the pins in the plug socket on the ECU (which get 12V from the battery via the EMS relay and fuse box) connects directly to another pin which connects to a wire which goes to the bike's earth bolt on the engine.
This is rather difficult to explain, so here's a scan of the wiring diagram. I've drawn a line to show where I think the short goes inside the ECU (from pin A6 to pin A35). I'm not certain of the pin numbers, but A6 definitely goes to earth somehow.
Ideally like to know it there are any tests I can do on my ECU to be sure that it is cooked before I purchase a replacement (second hand ECUs seem to be about £110 on Ebay). Any ideas?
 

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#23 ·
I'd be suspicius of the charging circuit once you do get sorted out. Overvoltage could have baked the battery and seen off the ECU .. Best bet would be a kindred Sprint spirit nearby that would be willing to loan you an ECU to try ? Have you tried asking nicely on the UK Triumph sprint site ? :)
 
#24 ·
Checking the charging circuit is good advice Pcdabbler, thanks. I'll do that when I get it running again. Also, if I haven't used up my permitted shed time I'll fit a battery charge indicator. It's time to go shopping for a second hand ECU...
 
#25 ·
Can anyone advise what numbers are significant when choosing a replacement ECU. I've spotted several ECUs on Ebay, but am not sure any of them would work with my '05 Sprint ST.
On the label on my existing ECU there's a large letter 'B' and numbers/codes for: VIN, TUNE, CALIB, DATE and PART.
Do I need to consider anything more than getting a matching part number, which is presumably the number called PART?
Many thanks, again
 

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#26 ·
As long as it's the same type of ECU, you should be able to flash it with the proper tune via TuneECU.

Cheers,
-Kit
 
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