'00 V11s, lost low beam, high beam, and horn

[Guest toutizes]

[First I'll mention that I changed all relays a while back, and that the bike has been riding quite well for a while. I'm in California and have about 18k miles on it]

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Hi All,

 

I lost the low-beam, high-beam, and horn on my '00 Guzzi.

 

The three are activated by switches in the same cluster on the left handlebar.

 

I have good battery power, for example no problem with using the electric

starter.

 

With a volt-meter and the bulb removed I measured 11.55v at the H4 socket

(exactly 11.55v).

 

However, if I put in the bulb it does not light up and after I remove it the

volt-meter shows only 0.25v at the H4 socket. A different bulb gives the same

result.

 

If I turn the bike on/off I measure 11.55v again at the socket and I can

repeat the experiment of inserting and removing the bulb and measuring 0.25v

afterwards.

 

Does this make any sense? Does this point to a particular place where the

problem could be?

 

I traced through the harness, checking resistance and voltage at various

points on the low-beam circuit and did not find anything obviously wrong.

After I'm down to 0.25v disconnecting and reconnecting any of the connectors

along the low beam circuit in the harnes brings back the 11.55v at the h4

socket.

 

While tracking I was a bit surprised to not find a relay on the circuit and

indeed the electric map for the bike does not have a low beam/high beam

relay. I gather this means that a few amps have to flow through the connector

on the handlebar?? Is that normal on these bikes?

 

Is there something else I could check?

 

Thanks in advance

Matthieu

 

'00 V11S

'86 SRX6

[callison]

You also lost your brake light. The power for the headlight, brake lights and horn are supplied by a red/black wire coming out of the headlight relay. Check that and if there is no voltage there under any condition, but there is voltage on the green/white wire on the same relay, replace the relay. Otherwise, check that the sidestand switch is actuating correctly. If it is ,then replace the starter relay. Even I don't completely understand the convoluted sidestand interlock set-up on the late model sports - and I've got 41 Moto Guzzi schematics I've re-drafted sitting on my web page. Guess I'm gonna have to sit down an make a logic flow chart one of these days...

[Murray]

I think you have a dirty earth somewhere or maybe the dirty fuse/connection. With no load it will supply 11.5 volts (little low to me) however with a serious current drawing load the dirty connection doesn't allow enough current to pass to power headlight /horn etc etc. Have you tired measuring voltage betweent he power contact for the headlamp and the earth contact instead of using any old earth? might be intresting.

[Guest toutizes]

You also lost your brake light. The power for the headlight, brake lights and horn are supplied by a red/black wire coming out of the headlight relay....

Nope, I checked that.

 

Break like is fine, and correctly switches on with either front or rear break. I actually did check the voltage on the read/black line, etc.

 

Oh, and I had removed the sidestand switch 2 years ago, i can't stand () these...

 

Thanks

[Guest toutizes]

I think you have a dirty earth somewhere or maybe the dirty fuse/connection. With no load it will supply 11.5 volts (little low to me) however with a serious current drawing load the dirty connection doesn't allow enough current to pass to power headlight /horn etc etc. Have you tired measuring voltage betweent he power contact for the headlamp and the earth contact instead of using any old earth? might be intresting.

THanks for the idea, I'll try that.

Matthieu

[callison]

Well, so much for me being the smart guy. If you have voltage on the red/black wire that pretty much leaves the connector for the handlebar controls. Normally, I would say it's the headlight connector itself at this point (mine was) but since you said the horn also does not work, that leaves the connector for the handlebar controls or the controls themselves. That's the only place where both the horn and headlight have a common tie in. The probability of a bad ground on a Guzzi is actually always quite high, but the horn and headlights do not share the same ground so I would not expect that to be the problem, but then again, it's a Guzzi so anything is possible.

[jrt]

I had a similar problem early on with my V11- in my case the switch had gone bad. Probably not what you wanted to hear- sorry. Have you swapped out the light's relay just in case it's that?

 

Jason

[jrt]

Any update, Matthieu?

 

J