Charging Light

[dbarb3]

Well new problem today

Charging light comes on and tach stops working.  Typically on a car would point to alternator.  With higher rpm it dims.

Where to start?

 

 

 

 

 

[docc]

Relay #2.

[docc]

Source a full set of "Best Relays", either OMORON G8HE or (more available): CIT

 

[docc]

This may still lead to a regulator, or even a stator fault, but the tachometer dropping out with charging failure is classic Relay#2 (plus Relay#1 on the early Sports).

[dbarb3]

Will give it a try but I have the new relays in I got from DP Guzzi

 

[Lucky Phil]

2 minutes ago, dbarb3 said:

Will give it a try but I have the new relays in I got from DP Guzzi

 

Check the relay holder, connectors and the wiring behind it.

Ciao

[dbarb3]

will do 

is the regulator under the front of the tank

[Lucky Phil]

1 minute ago, dbarb3 said:

will do 

is the regulator under the front of the tank

On the front subframe.

Ciao

 

[Kiwi_Roy]

If the Tach stops working check to see if the headlight's off as well, the regulator gets its reference from the headlight feed after the headlight relay.

If the reference is missing the regulator never turns on.

[dbarb3]

From reading other threads I test the yellow wires from alternator to regulator if other items check out??   Is meter set to DC   and what reading should I look for?

[docc]

The yellow stator wires are AC, IIRC. Pretty common that one of them detached at the stator (which can surprisingly hard to see on the bike with the alternator cover off).

[dbarb3]

here is the little bit know I know

Changed out relay 2  no change

Tach not working, headlight on

Charging light not lit

Battery engine off  12.15  Engine running  11.5 

Obviously not charging,  check wiring at alternator next??

 

 

[docc]

Simple enough to check the voltage on the yellow stator wires. The Workshop Manual says the AC voltage between the two yellow wires should be 15vAC at 1000 rpm, 40vAC at 3000, and 80vAC at 6000rpm.

 

 

 

[Weegie]

Pretty sure my Sporti has a similar system

Before checking the Alternator I'd make sure all the Reg/Rec wires are connected............At least on the Sport there are 2 which connect with a half assed jack plug arrangment that (too) easily pulls apart I'd also check the earth on the Reg/Rec and the condtion of the yellow cables from the Alternator too

You've replaced Relay #1&2 although it should be obvious but I'd check all the fuses, looks like some of them could perhaps cause issues

That's if I've got the correct wiring diagram

As @docc  states, easy to check Alternator voltage remember AC Volts

[Kiwi_Roy]

20 hours ago, dbarb3 said:

 

Tach not working, headlight on

Charging light not lit

Battery engine off  12.15  Engine running  11.5 

Obviously not charging,  check wiring at alternator next??

 

 

If you don't have a Voltage reference to the regulator the regulator cannot turn the charging light ON and neither can it turn on the SCRs to charge the battery, Check the black wire of the black / white pair, should be 12 Volts with the ignition ON

The Black wire plugs into the female of the M/FM pair, its Red/Black on the loom side, connects to the headlight circuit downstream of the headlight relay, its actually soldered to the headlight feed under the tank.   

The Male pin on the loom side goes to the charge light, the light will turn on if you ground that pin. The light gets +12 Volts from the same wire that powers up the Tachometer.

There are quite a few variations on the wiring but this is always the case, if you are looking at the M/FM connector on the loom side the Female should show the battery Voltage when the key is On (without this the regulator cannot work) the Male should also show the battery Voltage but if you touch it to chassis the charge light will turn On.

Make sure the regulator case is well grounded to the engine, don't rely on the black wire that goes all the way back to the battery, its just a token ground.