Some dash warning lights not working...

[Guest Martin Coogan]

Hi. I have recently bought a 2001 model V11 Sport.

 

The oil pressure and low fuel lights don't come on, and the charging light works half of the time.

 

I replaced the oil pressure sensor. The oil light then worked. I rode it, came home, started it the next day and the oil light was gone again...

 

I have replaced the bulbs. I have checked the connector under the tank on the right hand side - this looks clean inside and appears to click together properly. I cleaned the male contacts with WD40 and a cotton bud, and sprayed WD40 onto the female contacts from the front and from the back. I have jiggled the relays and swapped the first three around - no change.

 

The flasher, neutral and high beam lights work fine.

 

Does anyone have any idea what I should try next?

 

Thanks in advance.

 

Martin.

[motoguzznix]

Martin

 

The oil pressure switches used by Guzzi arre of very inferior quality. A new one often fails out of the box.

There are better ones aivailable that fit perfectly. Older BMW boxers use switches with the same thread and Hella has a better replacement in stock. I'm sure you will find more info when surching in the forum.

 

An other opportunity is the +supply for the control lights in the dash. There is only one red or red/black wire that supplys all lights in the dash, so well woth checking it.

[Guest Martin Coogan]

Martin

 

The oil pressure switches used by Guzzi arre of very inferior quality. A new one often fails out of the box.

There are better ones aivailable that fit perfectly. Older BMW boxers use switches with the same thread and Hella has a better replacement in stock. I'm sure you will find more info when surching in the forum.

 

An other opportunity is the +supply for the control lights in the dash. There is only one red or red/black wire that supplys all lights in the dash, so well woth checking it.

 

Thanks for your advice. I didn't mention that originally I had tried grounding the lead going to the sensor and the oil light lit up. Since replacing the sensor (and it not working past the first day), I tried grounding the lead again and it didn't light up. So I suspect the wiring or the bulb rather than the sensor. I've switched those bulbs round many times so far - it's a kind of torture! I'm going to re-test all the bulbs in the neutral light socket as that always works, to make sure none have blown. The sockets seem pretty fragile though...

 

Is the +supply wire common to the three lights in question only, or to all the lights including the high beam, indicators and neutral light (which all work)?

 

I am OK at mechanical stuff, but electrics are no fun...

 

Thanks,

Martin.

[callison]

Thanks for your advice. I didn't mention that originally I had tried grounding the lead going to the sensor and the oil light lit up. Since replacing the sensor (and it not working past the first day), I tried grounding the lead again and it didn't light up. So I suspect the wiring or the bulb rather than the sensor. I've switched those bulbs round many times so far - it's a kind of torture! I'm going to re-test all the bulbs in the neutral light socket as that always works, to make sure none have blown. The sockets seem pretty fragile though...

 

Is the +supply wire common to the three lights in question only, or to all the lights including the high beam, indicators and neutral light (which all work)?

 

I am OK at mechanical stuff, but electrics are no fun...

 

Thanks,

Martin.

 

Refer to:

1999 Moto Guzzi V11 Sport schematic

 

The generator light, oil pressure light, low fuel light and the speedometer and tachometer lights all share a common +12v from a red/black wire. That same wire also feeds the engine run/start switches, the front and rear brake switches, the horn and the high beam flash. If any of these work (checking the brake lights would be a fast easy check) you'll know that the fuse F5 is good. Unfortunately, the red/black wire is fed from the headlight relay and that in turn is fed by the starter relay. Either on of those could be a problem unless of course, turn signals, brake lights etc do work in which case it might be something a bit more insidious. Lest you cringe in fear of that statement, you should know that the illumination bulbs on the V11 Sport have a very inferior bulb socket design that has been known to fall apart and short out. That would be where I would look first. When you pop the bulb holder(s) out from the back of the tach or speedo, you should be able to remove the bayonet bulb without the whole thing falling apart. If it does, that's an indicator that things ain't right. The problem could lie somewhere else so I'm not going to give this reply as the universal panacea for your problem because it most certainly might not be, but it is worth a check.

[Guest Martin Coogan]

Refer to:

1999 Moto Guzzi V11 Sport schematic

 

The generator light, oil pressure light, low fuel light and the speedometer and tachometer lights all share a common +12v from a red/black wire. That same wire also feeds the engine run/start switches, the front and rear brake switches, the horn and the high beam flash. If any of these work (checking the brake lights would be a fast easy check) you'll know that the fuse F5 is good. Unfortunately, the red/black wire is fed from the headlight relay and that in turn is fed by the starter relay. Either on of those could be a problem unless of course, turn signals, brake lights etc do work in which case it might be something a bit more insidious. Lest you cringe in fear of that statement, you should know that the illumination bulbs on the V11 Sport have a very inferior bulb socket design that has been known to fall apart and short out. That would be where I would look first. When you pop the bulb holder(s) out from the back of the tach or speedo, you should be able to remove the bayonet bulb without the whole thing falling apart. If it does, that's an indicator that things ain't right. The problem could lie somewhere else so I'm not going to give this reply as the universal panacea for your problem because it most certainly might not be, but it is worth a check.

 

Thanks Carl. Turn signals and brake lights etc. do work, so the red/black wire sounds to be OK. The sockets appear to be OK, but sometimes when shoving the rubber surrounds back in the bulbs fall out. From what you and motoguzznix have said, the fuses and relays are not the problem. I think the problem is going to be the sockets or the bulbs. I'll re-test the bulbs in the neutral light socket. If they're good, it looks like repair or replace the sockets time.

 

Hmmm. A new instrument panel loom is £78. Other than that, maybe it's time to get an auto electrician in.

 

Thanks a lot for your help, I'll let you know how I get on.

 

Martin.

[BrianG]

I have replaced all of the dash lights with plug-wired LED units. The MG bulb sockets are known to disintegrate and short out the power supply fuse spoken about above, and those little bulbs have frail elements when pitted against the V-11's vibrations. LEDs also are pretty much a live-forever, vibration-proof unit.

 

I'm having the same oil-pressure sender unit issue, and trying to determine the proper replacement.