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2002 nevada club, electrical

D

driftershooter

Just got it firing!
Joined
Sep 21, 2012
Messages
15
Hello everyone, my names Colin from the UK. My Nevada has a funny electrical problem. When i put the lights on the idiot dash lights and tacho go off. This doesn't affect the running of the bike as it runs really well. Even when the lights are off i can get the same problem. My front left indicator can go off at the same time too. Very strange indeed. Crikey where do i start with this? :roll:
 
Electrical Gremlins!!!!! Old Jock will probably jump on this he seems to be the forums electrical wizard. My two cents says look for a bad ground or a loose / corroded connection.

Check the ground cables coming off the negative side of the battery make sure they are clean & tight and any other wires that connect to them are clean & tight also. You may have to pull tank, seat & side covers to get to the rest of the harness but every snap connector is suspect and needs to be pulled apart & inspected. Leave the battery disconnected (pull the ground wire off) when checking the connectors. Years ago Guzzi used the head light housing as a junction block for lots of electrical stuff and also as a grounding point, don't know if they still do. Think about where water might be running into a connection and causing corrosion, especially if the bike is kept outside or ridden in the rain.

Good Luck, Welcome to the Forum & please post your results!
 
There's a possibility (and probably a remote one) that the idiot lights and tach are using the headlight as a ground return. The resistance of the headlight bulb is very low especially when cold, so this would hardly affect the current through the others when in series. When volts are applied to the headlight the "virtual ground" for the idiot lights and tach is lost and therefore extinguish.
 
Thank you very much indeed, i will tke a look tomorrow and post my results. I did notice when i bought the bike that the earth lead from the battery went straight to the engine and not the frame so i have put an earth lead from the battery negative to the frame now too. Mind you made no difference to the tacho and idiot lights. Whoopy thanks for the pointers lads. I'm impressed with this site, donation on the way!!! :woohoo:
 
No luck as yet, the connections are very clean and tight. I'll have to pull the tank next and check the connections underneath. As these are covered i don't think i'm going to find a problem. Would it be wise to earth the idiot lights and tacho seperately?
 
john zibell said:
Having extra good grounds never hurt.
Click to expand...
Whats the best way of doing it, tapping into an existing black earth wire and attaching it to the nearest frame screw or bolt fixing with a connector. I'm assuming all black wires are earth? Thanks Col.
 
Hi Colin

First you stated you have lost Hi beam, so first thing I'd do there is open the headlamp shell and check both the bulb filaments for resistance if one is open (Hi resistance) then the filaments burned out. When you are in there check that everything is connected properly, nothing loose and no disconnected wires.

I assume you still have Lo fuel, neutral and oil pressure warn lights as these ground locally at their respective switches; but you have lost turn signal, Hi beam warn and instrument pilot lights.

Now I don't know the Nevada but going from Carl's diagram

http://www.thisoldtractor.com/guzzi007/schematics/2002_Nevada_series_2.gif

There is as previously posted a paralleled wire going to provide a ground for all of this stuff (not sure about the headlight though but its possible too). If that diagram is accurate and the ground wire there is bad or the AMP connector faulty or separated (14 on Carl's diagram) then you will lose the lot. If the wiring is as per the diagram you should also have lost the indicators too............have you?

As far as running additional earths I'd run from the device to a frame or engine point. Grouping them via a connector bloc is another way of going about it, parallel them up then take a wire to a convenient point on the frame or engine

I'm sorry I got no idea where that AMP connector is but I would hazard a guess its around the headstock or underneath the fuel tank. It's marked as Dashboard A so you could follow the wires out the dash and trace them back to the plug

That's my starter, post up when you get a chance to check and we can take it from there

John

ps I agree an excellent site for all things Guzzi and Todd and John Z are terrific
 
Colin

Just to add that if the ground connection I referred to in the previous post is loose or has corrosion, its very possible to get strange things happening as you describe.

Another question, when you switch on the headlight is it "yellowish" or generally a bit dull?

If the earth isn't good and introduces a resistance to the circuit then you don't get the full voltage across the devices and if its sufficiently poor stuff will not work at all.

John
 
Hi John, I don't have oil pressure, high beam or nuetral lights on the dash. The indicators work fine. The headlight is good but no high beam. I have checked all the connections around the headlight area and at the back above the rectifier. All good. I havent taken the tank off yet to trace the loom back to a possible connector underneath but will do tomorrow if time allows. Thanks Col.
 
Hi Colin

Looking at another wiring diagram it sounds like it could be the positive supply that's the problem, from what you tell me

I am guessing that the indicator warnings are fine.

First I'd check to see if all the instrument lights are good you may have some failed.

From the wiring diagram in the owners manual for a Nevada the pos supply for all the instruments with the exception of indicators and main beam and the instrument lights all take their feed from a common wire coming from the rectifier. It appears to be red/black.

This wire also supplies the pos feed to the electronic tacho. So is the tacho working fine?

When you have the cluster opened check to see they are all connected.

The sidelight, tail light and instrument lights all come off fuse 1 check its good, then go through the switch and supply the tail light, sidelight and instrument bulbs so they should all work together. The Hi/Lo beam are relay operated and use fuse 2.

Is the sidelight and tail light working when they should?

I am still struggling a little as
a) I'm not familiar with smallblocks
b) Some of it just is sooo different from the way I am used to seeing things done.

Anyway let me know how it goes and some pictures would certainly help to asses general condition of the wiring.

Unfortunately a lot of Guzzi owners tinker with the electrics, that's fine if you know what your doing, quite a lot don't. I am not saying don't troubleshoot of course you should and post up what you find. If you ask for help here if I can't help there are plenty more able than me.

John
 
Hi John, tail and side lights working. The indicators all work as they should. The tacho and speedo lights work fine with good illumination. The tacho wont work at all when the lights are on and intermittent when they are off. Mind you I rarely ride with lights off so my tacho is dead most of the time. My idiot lights sometimes work when the lights are off or on. Mind you, saying that they haven't worked at all for the past two ride outs so may be the bulbs have now finally blown.
Also now this is strange, the tacho worked for a bit at the start of a ride, then it died off after a mile or so. If I stopped for a coffee somewhere and put the bike on the centre stand it would work again for a short time whilst riding then die off again. It almost seems that the main stand is supplying a tempory earth haha. :shock:
 
It sounds like a loose connector to the instrument light supply as this also supplies the tacho and you say its intermittent/not working most of the time

There is a 10 way connector Dashboard B and that's where I'd look first, as I said probably around the headstock or under the tank

John
 
I looked at the wiring behind the idiot lights and both clocks, all fine and tight. My idiot lights and tacho still go off when the main lights are switched on. I have no main beam or rear stop lights now. I'm taking the tank off tomorrow morning to investigate the wiring loom from under there all the way back to the battery. I will also check the earth on the tail light. I've bought another earth strap so will put that some where, may be the rectifier fixing point to an engine fixing. Hope i find the problem.
 
Looks like the dash lights and indicators are using the headlight bulb as a ground path. As soon as you turn on the headlight, both sides of the lights that go out have 12 volts applied. Check the schematic and improve the grounding of the dash lights/indicators.
 
Do you think the blown headlight bulb has something to do with this fault. I wonder if the grounding goes to the rectifier now the headlight backing is plastic instead of steel. I was once told to improve the grounding of the rectifier by grinding the paint off the fixing points. I did that but no change. Not sure where these ground points ground too!
 
Oh dear it just gets better doesn't it NOT!! :roll:

Good suggestion from John Z on the alternate ground paths. I'm still struggling with the small block wiring a bit.

According to the wiring diagram, the earth line for the indicators, headlamp (Lo, Hi and park), tacho and Hi beam warn are all connected so it's a distinct possibility. The line according to the diagram goes to a 5 way AMP Superseal connector labelled Dashboard A, on pin 5 of the connector. If that is not grounded then that could cause a bunch of weird shit. I have no clue physically where the actual grounding point is.

If you can locate and open that connector and then ground pin 5 with a test wire from plug to frame and see if anything changes it might help to isolate the fault.

Don't think a blown headlamp bulb would cause any of it.

Usually additional grounding at the regulator/rectifier is to make sure the regulator "sees" the system voltage properly. If it does not then there can be poor regulation and a higher than desirable charging voltage. This results in blown bulbs and can cook the battery too. I don't think (yet) that this has anything to do with your existing woes on the bike.

When you say no stop light I ASS-ume you mean brake light, check with both footbrake and lever brake to see if the light operates. I notice that the pos feed for the lever operated switch to the brake light also comes from the same supply that feeds the idiot lights so this problem is all connected. For the life of me though I am having difficulty pinning it down

John
 
Well took the tank off today, checked all the said connections right back to the battery, all clean and tight. I then decided to inspect the loom by moving it with the ignition on to see what happens. I got as far as the wiring loom then comes from the fusebox. The dash lights came on whilst moving the loom at the bottom where it curves. I had to take the battery out so i could get to the suspect loom and carefully strip the black insulation off it. There was a heck of alot of wires to inspect there, I got my torch out and found a suspect set of wires. It was 3 red wires connected to 1 with what looked like a shrink type join over the top of them. I then decided to carefully cut this join away and duly sliced my index finger, damn! The wife took me to hospital as i was bleeding quite bad. Got repaired with a few stitches then came back to the job. I stripped back all four wires and joined them all together with a block connector. I could have done with a nice 3 into 1 connector but no one did them, not even maplins. Anyway battery on and BINGO!!!! My dash lights, stop light, headlight,main beam and idiots all came on. Problem now solved. Not a suspected earthing problem, just a very bad join inside the loom. Hohar i'm a happy bunny now!!!! :lol:
 
Congratulation on finding the electrical gremlin. Sometimes you just have to get lucky with an electrical problem. Sorry you had the bad luck with the knife, but that too will heal.
 
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