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Battery draining through ECU


dlaing

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Oh, dear.  :(  I'm showing about 10 volts and 0.76 amps.  What is it thinking about while we're sleeping?

The #3 fuse (regulator) shows 0.25 volts with no measurable milliamps. That fuse looked as if it had been quite hot. Probably when the regulator went toes up last year.

 

EDIT:  Speaking of the wiring diagram, Where is the head temperature sensor? There appeears to be one on the right cylinder head , inboard, with a blue connector. :huh2:

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Oh boy, I have really been chasing my tail. :angry:

Thanks Des and Docc for stopping me from missing more of the riding season! :bier:

I just don't understand how my bike previously started after a month of sitting?????

When I replaced my regulator, my number three fuse was starting to melt, and with the new regulator, I got too much resistance on that line to get a good charge, so I had to run a bypass to the battery.

I suspect the 0.25V reading you get is just back current through the Diodes of the regulator.

Maybe this current draw through the ECU that the three of us have is not normal, and we who have cooked our regulators also cooked our ECUs :huh2:

Anybody else want to check the number one fuse voltage?

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EDIT:  Speaking of the wiring diagram, Where is the head temperature sensor? There appeears to be one on the right cylinder head , inboard, with a blue connector. :huh2:

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#54. Really. MG calls it the oil temp sensor.

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I thought the oil temp sensor resides by the timing sensor on the right side of the block, top. If that's not the oil temp sensor what is it??

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If that's not the oil temp sensor what is it??

 

There you have on front the timing sensor, and a bit back with one wire on it, the oilpressure switch, the one that lights your oil light.

 

So your regulator is surely 100% ok? if you disconnect that one?

 

measuring voltages acros a fuse doesn't tell much. But amps do. who you say 0.072 amps across fuse one, that means 12/0.072= 166 ohms resistance.

 

So when you pull the ecu and measure between pin 17 and any other pin, do you have a resistance like that?

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So when you pull the ecu and measure between pin 17 and any other pin, do you have a resistance like that?

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No, I get 9.58 M Ohms between the ECU ground wire and the 17pin. So it there must be some switching going on inside the ECU.

EDIT or more exactly

9.57M at the 17 pin harnass disconnected

9.58M at the #1 fuse harnass connected.

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Ok, thanks, I see it now . The "Oil temp" is taken from the right head and the "oil pressure" fom the left-front-top block.

 

Again, I wonder , what is the ECU doing full time? Is it reading barometric pressure full time? It is my understanding that there is a baro sensor within the ECU.

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Again, I wonder , what is the ECU doing full time? Is it reading barometric pressure full time? It is my understanding that there is a baro sensor within the ECU.

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There is a barometric sensor in the ECU, but there should be no reason to read it when the bike is off.

I don't know why it would need power for anything.

Some cars with fuzzy logic will store driving habit, and to erase the memory of those habits you disconnect the battery.

Maybe our ECU is more complex than we imagined...

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Hello David

 

I measured mine and got also 10 V at F1. The current along the fuse was 0,0075 A which is one tenth of yours.

Drawing 0,072 A out of the battery sums up to 12 Ah in one week, so the battery should be completely empty.

According to this, my bikes battery should be empty within ten weeks, which really occurs. Better than yours, but still not good. There is some fault in the electrics to be detected.

 

Does this current flow via the ECU ground cable? Then a possible solution would be to switch the ground cable by a relay that is activated by the plus at the ignition switch. Does not cure the problem but prevents the draining of the battery. :homer:

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Thanks for checking.

I thought the drop in voltage was somehow proportional the current, so the 0.0075 does not seem to correspond to the 10V. But I really have no idea what the math should be to determine amps through voltage drop, or if it is even possible :huh2:

Are you sure you read 0.0075A?

I will double check my reading...

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It may be academic, but I'm going to go about this from a different angle.

 

I'm going to record the voltage drop at the same time every day over a couple of days, then pull the #1 fuse and check it at the same interval.

 

That should at least isolate the problem.

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Don't know what you are doing or measuring, but 10V sound quite odd to me.

 

The F1 fuse is or at least should be directly connected to the battery!

 

You def. should see 1:1 the battery voltage! Regardless whether you pull fuses or not, a good battery assumed you will see 10V only under currents the starter could produce! This would mean your ECU is buzzing some solid 80 Amps or so.

 

What is wrong with my point of view? :huh2:

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