Electrical Problem

[gstallons]

I would install them in all postions

[MartyNZ]

No headlight? No tach? Also check your ignition switch contacts.

Yes, I opened up the ignition switch, cleaned and lubed it, but it looked pretty good. It's a tricky thing isn't it.

...Along with considering the Run Switch's feed from the Sidestand Switch. If it acted up rolling in gear, then straightened out parked it could be that the alternate current path through the Neutral Switch/ Relay#3 temporarily "solved" the problem.

Which 3 positions get the High Current Relays?

I cleaned and lubed the run switch, but I don't think it was the problem either. Things got a lot better when I replaced the 3 rear-most relays.

I would install them in all postions

Yep, all 5 relays are now G8HE.

-

So the bike started fine.

Tach working? Yes.   

Headlight working? No.  <_>

Oh wait, the headlight is still sitting on the bench.  Tailight works, so all good now.

[cash1000]

Can these electrical problems be passed from bike to bike after our 2 bikes co-habitating in the same garage for a few hours?

[MartyNZ]

Can these electrical problems be passed from bike to bike after our 2 bikes co-habitating in the same garage for a few hours?

Well,  I didn't want to say anything bad about your bike, but now you mention it...

[Kiwi_Roy]

Marty, I believe your 2003 will be wired differently from Cash1000s 2001

Instead of the headlight current flowing through two relays in series it will have the Start relay N/C contact 87a feeding the coil of the headlight relay not the 30 contact (100 milliamps vs 4-5 Amps)

 

The Start relay 30 contact will be fed from the ignition switch rather than direct from the battery through a fuse.

 

The easy way to confirm which you have is pullout the start relay and see if the 30 contact is alive with the key Off.

 

Each way has it's merits, the 2001 will never suffer from Startus Interuptus but charging is more flakey unless you have an after market direct connect regulator.

The 2003 will eventually suffer from SI through too much Voltage drop.

 

The starter solenoid would like to inrush 40 Amps or more, the circuit resistance needs to be

Excessive resistance is what causes almost all modern Guzzis to fail to crank.

[MartyNZ]

Marty, I believe your 2003 will be wired differently from Cash1000s 2001

Instead of the headlight current flowing through two relays in series it will have the Start relay N/C contact 87a feeding the coil of the headlight relay not the 30 contact (100 milliamps vs 4-5 Amps)

 

The Start relay 30 contact will be fed from the ignition switch rather than direct from the battery through a fuse.

 

The easy way to confirm which you have is pullout the start relay and see if the 30 contact is alive with the key Off.

 

Each way has it's merits, the 2001 will never suffer from Startus Interuptus but charging is more flakey unless you have an after market direct connect regulator.

The 2003 will eventually suffer from SI through too much Voltage drop.

 

The starter solenoid would like to inrush 40 Amps or more, the circuit resistance needs to be

Excessive resistance is what causes almost all modern Guzzis to fail to crank.

Thanks Roy, you are right again. My bike seems to be wired like a 2004 model. Start relay terminal 30 is only powered when the key is on. 

The resistance from start relay terminal 87 to engine ground is 0.3 ohms, which I hope means that I should be cranking for a while yet.

 

[Kiwi_Roy]

Marty, that 0.3 Ohms you read is the two coils to chassis a 1.05 Ohm direct to chassis and 0.25 in series with the starter winding to chassis.

 Where we get all the problems is from battery + to the relay terminal 30, that goes through the ignition switch on your 04, if you clean the switch every year or so it should be ok.

 

I will sketch out how you can re-wire the later bike relays to avoid the ignition switch

[bbolesaz]

If the spade lugs on the relays were all the same size, the rewire could be simply re-arranging the terminals. I used Posi-Lock connectors on mine, JIC I want to go back to the 2004 style wiring.

[Kiwi_Roy]

Bbolesaz,

Do you think the later wire with the start relay through the switch is more reliable?

I always felt the earlier wiring was better for starting, for Voltage regulation not so much.

 

I don't want to suggest something weird.

[bbolesaz]

For the starter circuit, I think the earlier wiring not routing through the ignition switch is preferable. So I agree with your assessment. 

 

As for the voltage regulation, while the 1999 schematic voltage regulator has a separate sense line tied to the headlight relay driven lighting circuit, the 2004 schematic (and my 2002 Scura) did not have this regulator sense line.  On 2004 schematic, the sense is common with the battery charging line.  Sensing from the headlight circuit is probably a preferable method as it can account for the lighting circuit loading and compensate the alternator output for that. But, I think history has shown it is less reliable because of the long wiring route the sense voltage has to make.

 

The 2004 regulator schematic and my 2002 regulator (and the EME unit I replaced it with) does not have the sensing line so the sensing wiring is a moot point.

 

So, in the end, it seems you have a choice of -

1999 wiring - good starter, and maybe better but less reliable voltage regulation.

2004 wiring - maybe startus interruptus and maybe a more reliable regulator.

 

So, I've rewired only the starter and headlight relay circuits. I will also re-iterate that my 2002 Scura closely matched the 2004 schematic.

 

On the "livin easy" issue - The circuit here is intended to shut the headlight off when the starter is engaged, to allow more electrons to the starter and maybe start on a weak battery that wouldn't be able to supply the starter and headlight at the same time.  The 2 wiring diagrams achieve that in 2 different ways.

 

In the 1999 diagram, the battery connects to the center pole of the relay(30). The relay either switches the battery current to the starter(87) or to the headlight (87A).  The headlight relay then forwards that to the lights based on the key switch.  This one was called living hard, because the headlight relay was passing the lighting current during normal run time.

 

In the 2004 diagram, the battery takes a route through the switch but still connects to the center pole of the relay(30). It again switches the battery to the starter(87). However, in this case, when the starter button isn't pushed, the 87A terminal supplies much less current to the COIL of the headlight relay.  Hence, living easy.  The headlight relay center pole (30) has it's own connection to the battery.

 

In any case, the headlight relay still passes all of the current for the lighting system.

 

So, in the 1999 case the lighting current passes through both the starter and headlight relay.  In the 2004 case, only through the headlight relay.  So, OK, maybe the 2004 case is preferable.

 

Unfortunately, you cannot modify the 2004 starter schematic without also modifying the headlight relay schematic. (Yes, I started rewiring stuff without really thinking it through and found this out the hard way.)  The headlights could not be turned off.

 

Since the headlight relay passes the lighting currently continuously anyhow, and I've used the same super high quality forum approved relays in all 5 slots, I don't think it is an issue if the starter relay also passes lighting current while not starting.  My $0.02

[Kiwi_Roy]

Bbolasaz,

                 I think you summarized both systems very well.

My 2001 of course had the early wiring and never suffered from Startus Interuptus but I could never get the regulator to work reliably until I fitted an after market regulator without the Voltage sense.

What I would suggest with the 2004 wiring would be to feed the Start relay 30 from the headlight 30 next door, this would give improved starting as Fuse 5 feeds the headlight relay direct from the batery, not through the switch.

 

Then to deal with the headlight relay

The headlight relay coil 85 & 86 could then be wired between the ignition switch and the solenoid coil so when the key is turned on the relay closes, the 100 mA the coil draws would have no effect on the solenoid.

When the start button is pressed the start relay puts 12 Volts onto the solenoid so now it bangs in. The headlight relay coil has 12 Volts at both ends so it drops out until cranking is over.

 

Note: none of the relay Normally closed contacts are used, these are not rated as highly as the Normally Open ones, I have always suspected they are the main cause of erratic voltage reference on the earlier bikes.

 

BTW I first became aware of the ignition switch problem when my bike started to run really rough, when I measured the switch it was over 18 Ohms, a 2004 would have long quit cranking at

[bbolesaz]

Roy, I like that your solution doesn't route lamp power through 2 relays. But in the end, I decided to simply copy the 1999 wiring.  The G8HE relays are good for 20A on the normally closed (NC 87A) side and I don't have the voltage reference.