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Discussion Starter #1 (Edited)
I did something truly stupid and reversed polarity when hooking up the new battery. The 40 amp fuse blew, and yes, there were sparks.

When I finally figured out my mistake and when everything got reconnected properly i got a weird condition, and a no start situation:

-the oil light stays on, even with the key is out
-when i turn the key to the on position, only the battery light joins the oil light. The display does not cycle through and other lights do not come on. Nothing happens when i press the starter.

Oh, yeah. I have the new SPU, but maybe i fried that.
:(


Here is what i tried, without success:

-replacing the blown 40 amp fuse
-trying to hook up the original battery (thinking that i fried the new one)
-checking all the fuses under the tank (right side). All are ok.

Did i fry the EcU by reversing the polarity, or maybe just a relay?
Any clues about the weird warning light condition?
Do i still have something crossed up?

I do belive that the cables are now connected properly. Positive cables with the red rubber cover go to the positive terminal, and the two black cables coming out of the left side go to the negative terminal. I have some accessories hooked up. My led aux lights were on without the key, as well, so something might have happened to the "bridged ignition" circuit.

Not feeling terribly proud of myself....
 

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You fried the diode. It is located at the starter relay. You see it. It looks like a bare piece of wire. It's a $.10 fix.
 

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Discussion Starter #4
You fried the diode. It is located at the starter relay. You see it. It looks like a bare piece of wire. It's a $.10 fix.
Thank you.
I have located the starter. It is between the alternator and engine block. It has one fat cable coming from it, and it connects to the "M" symbol at the block located to the rear of the battery. Where is the starter relay located, along with the bare piece of wire/diode? Is it at the same block that houses the 40 amp fuse.....with the B and M terminals on it? Or is the starter relay hiding next to the starter?
 

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Discussion Starter #5 (Edited)
I think i found the diode. This thread pic shows it. Now....i pried the black insulation off, but do i need to cut the wire to replace the diode?
 

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Discussion Starter #6
Here is a better pic of the diode. It is tiny! Do i just pull the bastard out and then jam the radio shack replacement back into the brass contacts? ImageUploadedByMotorcycle1385348151.317010.jpg


Sent from Motorcycle.com App
 

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In the automobile world, when the battery connections are reversed, the Alternator diodes are fried along with several other things. I'd start with what is called a "fusible link". This is the savior between an electrical fire and nothing when an alternator shorts. Most likely you have fried the engine management system along with the spu, any diode and fusible link. I don't envy your task.
 

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That diode acts as the fusible link. T do the job correctly, you should pry the brass connectors out of the plastic fittings, solder the new diode in place, and re assemble. You could get away with soldering the new diode to the legs of the old one. You can't just pull the old one out. It is soldered in.

On the F4 it is extremely unlikely you have done any other damage. The Brutale is a completely different story.
 

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Discussion Starter #10
As long as stupidity only costs money....i will be alright.
:)

In the automobile world, when the battery connections are reversed, the Alternator diodes are fried along with several other things. I'd start with what is called a "fusible link". This is the savior between an electrical fire and nothing when an alternator shorts. Most likely you have fried the engine management system along with the spu, any diode and fusible link. I don't envy your task.
 

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I've never heard of a diode being used as a fusible link. Maybe so in this case. A diode is a device that only allows electricity to flow in one direction. Let us hope that is his only problem. I've switched old British cars from "positive earth" to the more common "negative earth", and there are lots of little goodies that need attention when that is done. Instruments need to be changed, radios, voltage regulators, fans, alternator diodes, etc etc.
 

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Fusible link is probably the wrong term. Sorry. On the F4 whenever anyone crosses the battery cables it's that diode that fails. I know of no case where the problem is worse.
 

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?

I'd do it CAG's way, clip the old leads and solder the new diode to the old legs.....done!
:drummer:
 

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Discussion Starter #14
No dice. I have installed a new starter relay diode and i still get the same condition with the battery reconnected:

-oil light on with the key out of ignition
-batt light on with the key in the start position

No clicking, display cycling, just a dead bike. Sigh.
I have my old blue spu. I will try to swap that out next.


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Discussion Starter #15
Dealer says that frying the ECU on a Brutale when reversing polarity is common.

Anyone have a used ECU?

I have also emailed chris and x-bikes in the UK to see if I could maybe try the unit that helps with the throttle snatchiness.
 

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Try CAG or ebay if he doesn't have one.

I have one if you get really stuck, but I'm going to guess that as it's from my 750 it would only work if your chip is ok and can be put into it.
 

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I don't have an ECU for an 06. I have 07 and later, but that doesn't help.

On the F4, I discovered thanks to Chuck, there are actually 2 diodes. I'm not sure on the Brutale.

Before you go swapping buying parts, get in touch with him. He is a genius at reading wiring diagrams. Ed is too. Try which ever one is less busy.
 

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Dealer says that frying the ECU on a Brutale when reversing polarity is common.

Anyone have a used ECU?

I have also emailed chris and x-bikes in the UK to see if I could maybe try the unit that helps with the throttle snatchiness.

Before buying parts you could ask your dealer to test te bike with a new or used ECU. Or ask one of our friends at the forum.

Once you've located the problem I can recommend Startwin, a site sponsor.

Good luck !!

Cheers,
 

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Did anyone ever find the solution to this problem? I seem to be running into the same symptoms, although it was only caused by the bike being off the tender for a while, killing yet another Yuasa battery.

Oil light is partially illuminated with a fresh Shorai battery and no key in the ignition and kill switch in the "off" position. With the kill switch in the "on" position, the battery light, neutral light and kickstand light are illuminated brightly (still, with no key in).

With the key in the ignition to the "on" position, all i get is the same bright lights as above.

I'm stumped, but this seemed like a problem that's had enough time to have found a solution I can latch onto.

Thanks!
 
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