I grounded positive batt post to ECU. with an allen wrench

[murphy3303]

I was adding a battery tender pigtail to the battery posts on my 2000 V11 sport. When I was making the final turns on the positive battery terminal screw the allen wrench touched one of the bolts that holds down the ECU unit.

The bike will not start now. I turn the key to the on position and I have headlights,horn,turn signals,dash lights and neutral indicator. What i don't get is the fuel pump priming and the starter won't turn over.

I checked all the fuses to see if any blew, but all are good.

 

What next?

[richard100t]

Check the relays under the seat too. Hopefully you just fried a relay.

[helicopterjim R.I.P.]

That happened to a friend of mine - it fried the ECU. Your situation sounds maybe less dramatic but prepare for the worst. I hope it is only a relay!

[murphy3303]

OK can do. First question, how do I test the relays. Second question, which Relay should I start with.

 

Thanks for the help.

[gstallons]

Start swapping relays around if you do not have access to a new one. Exchange #1 with #2: if it does not start, swap them back. Exchange #1 with #3:if it does not start,swap them back. Repeat the process until you have changed all of them. You can do this any any order as long as you have swapped them all.

Please put new fuses in the fuse panel too. I would hate for you to have a blown fuse. I don't know if MG has fusible links in their wiring system. I will look today.

[murphy3303]

Thanks for the suggestion about swapping around the relays. I have swapped out all of them with no change in the symptoms.

I will also replace the other fuses in the bike, just to be sure.

I did find a link on the other forum about for replacing the relays. http://www.dpguzzi.com/relay.htm

 

Thanks for looking into a fusable link in the system.

[guzzimeister]

Thanks for the suggestion about swapping around the relays. I have swapped out all of them with no change in the symptoms.

I will also replace the other fuses in the bike, just to be sure.

I did find a link on the other forum about for replacing the relays. http://www.dpguzzi.com/relay.htm

 

Thanks for looking into a fusable link in the system.

I don't think yuou've blown your ECU, it's either a relay or fuse connection. Check that the connectors for the relays especially have not pushed down into the relay block so you have an open circuit. Fuse block is also prone to the same problem, I have +ve earthed my ECU a few times, I can't see how it could hurt it. If necessary disassemble both blocks and plug reklays/fuses straight into the cfonnectors to make sure they are actually connected. I had the same problem and this is what cured it. Guzzi use really shit quality Lucars, Cheers Guzz

[Dan M]

The case of the ECU is grounded so it is unlikely you did any damage. Shorting the positive post directly to ground will not hurt fuses or relays because there is no fuse between the B+ post and the battery. (you would have to short a circuit after a fuse to blow it) Is it possible one of the wires did not get reconnected to the battery post when you hooked things back up? One eyelet may have dropped down when you pulled the bolt out.

[Cliff]

You should check your wiring harness from the ECU and the ECU's earth strap. Its possible some wires became like light filaments as the short circuit current could exceed 100A.

 

Even open the ECU's wiring harness outer wrapping to check the integrity of the wires inside.

[emry]

You should check your wiring harness from the ECU and the ECU's earth strap. Its possible some wires became like light filaments as the short circuit current could exceed 100A.

 

Even open the ECU's wiring harness outer wrapping to check the integrity of the wires inside.

 

Second. The grounding wires from the ECU case are small. Very small for a direct battery short.

[Kiwi_Roy]

You should check your wiring harness from the ECU and the ECU's earth strap. Its possible some wires became like light filaments as the short circuit current could exceed 100A.

 

Even open the ECU's wiring harness outer wrapping to check the integrity of the wires inside.

 

Second. The grounding wires from the ECU case are small. Very small for a direct battery short.

I would hope it's something that simple also. The ECU is rubber mounted so it relys on the small ground strap for it's battery Negative connection.

Check for voltage between the ECU case and chassis (or battery negative) with ignition ON, you shouldn't see any.

In future allways disconnect the battery negative first to avoid a short.

 

Test Point Layout.pdf

If it's not the ground strap heres a drawing that may help, unplug relays 4 & 5 then check for voltage at the 30 pin in each relay base to chassis, let us know what you see.

 

Roy

[fotoguzzi]

this is dumb.. but is your kill switch activated?

[richard100t]

this is dumb.. but is your kill switch activated?

LOL That sounds funny BUT it could definitely be the easiest problem to fix! I wish I would have thought of it.

[Kiwi_Roy]

this is dumb.. but is your kill switch activated?

LOL That sounds funny BUT it could definitely be the easiest problem to fix! I wish I would have thought of it.

First rule of electrical troubleshooting - check the stupid stuff first, I don't know how many times ignoring that has cost me hours.

[murphy3303]

First, before I admit to anything, I would like to thank everyone for their input and ideas.

I very much aprecitate this fourm and the people who moderate and contribute to it.

 

But yes, in my panic I did not check the kill switch, which is was activated.

I turned it off and the bike starts and runs just fine.

 

Thanks again to everyone.

 

Murphy.