Dash lights

[cash1000]

I will try again

[Scud]

Not sure what's going on with that foamy substance - haven't seen such a thing in my gauges. That might indicate that somebody else was trying to solve the problem with the tach - but I don't think it can explain the other symptoms you originally described.

[cash1000]

Not had much time to work on bike lately but what I've found so far is Red/Black wire has 10.68 v with ignition on but bike not started.

If I detach wire from one horn on outer side of bike then the other horn goes. I've tried pulling out the connectors that attach to the relays but no go. I used tool Roy describes.

Plugged in new relays but this made no difference. Checked ignition blub by swapping with another blub still no go.Still need to check grounding.

[Kiwi_Roy]

Not had much time to work on bike lately but what I've found so far is Red/Black wire has 10.68 v with ignition on but bike not started.

If I detach wire from one horn on outer side of bike then the other horn goes. I've tried pulling out the connectors that attach to the relays but no go. I used tool Roy describes.

Plugged in new relays but this made no difference. Checked ignition blub by swapping with another blub still no go.Still need to check grounding.

10.68 Volts seems low, the red/black wire should be just a little (~0.6) less than the battery Voltage, I am guessing the headlight relay terminal 30 on your bike is fed through the ignition switch.

Try for power there with the key Off

I think if you clean the ignition switch it will improve things, the grease goes hard after a few years and tends to hold the contacts apart.

It's quite easy to remove the switch, first remove the battery negative leads so you don't accidentally short something out

There are two Philips screws holding the black switch block onto the lock part, Look from underneath around towards the rear of the switch, take those out leaving the lock behind.

Prize the back off then tilt out the white switch plate, wipe out all the old grease and replace it with fresh Vaseline.

You can unplug the switch from the loom, I usually just do it still attached to the bike.

When you put the switch back together anchor the wires so they don't flex where they are soldered to the plate.

 

When you remove one of the horns this leaves more power for the other to work correctly, I think this may be a symptom of a dirty ignition switch also.

If you really want your horns to work well add a relay with the coil fed from the two wires that originally went to the horn (21) Run a new fused 16 gauge wire to terminal 30 of the relay and feed both horns from the 67 terminal with the other horn terminal to chassis.

 

The Generator (ignition) bulb is fed from the same Red/Black wire.

Find the male/female connector where the regulator plugs in looking at the loom side the female should be +12 (key On) and if you touch the male pin to chassis the light should go. Does the 

Voltage on female dip down when you do that?

With the key Off you should be able to measure the bulb resistance between male & female, I'm guessing 50 Ohms or less.

I have seen regulators where the charge light output was burnt out, they still charged ok.

 

 

http://www.thisoldtractor.com/guzzi007/schematics/1999_V11_sport.gif

 

http://www.thisoldtractor.com/guzzi007/schematics/2004_V11_Sport_Catalytic.gif

 

Update:

            The bike has an aftermarket direct connected regulator with no connection for the charge light.