Yet another Alternator question, how to find the "L&quo

[Outatime]

Hello Everyone! Long time no see!

Right, so I got a new alternator from SpecialTauto. Hoping that this will be the last electrical problem of all sorted in one go....

I worked out where the B+ connects to, but I am stuck with where the "L" thin wire is (from the original wires in the car)

The old alternator I have has the following connections:

Ground (via the mounting bolt and such)
B+ (a screw/nut at the back of the alternator)
L (a thin, either red or white wire... i mixed up the two and don't know which is which. It connects to the top of the voltage regulator)
B+ (a thin, either red or white wire... i mixed up the two and don't know which is which. It connects to the top of the voltage regulator)

The new alternator has:

Ground
B+
L

Are there any ways I could work out which of the two thin wires (from the car) is the "L" wire? Or should both be connected to the "L" connection of the new alternator?

I tried measuring them both, but the results confuses me:

ignition off:
both reads 0V

ignition on (engine off):
both reads battery voltage.

Any help would be greatly appreciated!

Many Thanks!

[bozzzydmc]

Ground Through alternator mounting bracket
B+ Big bunches of brown thick wires
L small brown / yellow wire ( to alt light on dash )

Your spare 'small' brown wire is just left capped off and is not needed

go back to the wiring on the main car looms and not any new bits extended to the previous alternator, these colours are aftermarket ones

Did you not get any fitting instructions with Johns Alternator matey?

[Outatime]

Thanks Mike!

(Oups, just found that I posted in the wrong section! Sorry!)

I have seen this diagram before. But the wires on my D is white and the other one is red. Which is why I can't work out with the colours.

Is there a smart Multimeter way to check which is which??

[bozzzydmc]

Should be brown and brown / yellow ...route back to the wiring on the main car loom and not to any new bits extended to the previous alternator, these colours sound like aftermarket ones

[Outatime]

No fitting instructions at all.... He might have forgotten. Have you got a copy you could send to my email??? (pretty please! )

I will try to trace it down then... but it seems that it goes all the way to no where! :evil:

[Outatime]

On another note.... is it dangerous to test connect the two wires with trial and error??? Or is this configuration safe to do so??

I read from somewhere that if this L wire is not connected to the right place, and the ignition is on... the voltage regulator will burn in 30 seconds or so (is this true?).... that's why I haven't tried it yet.

Can someone please confirm that this is safe or not to trial and error?

[NickT]

With the alternator ELECTRICALLY DISCONNECTED (ie no wires attached to it yet), apply 12v to your white wire and see if this lights up the alternator warning lamp on the dash. If it does then this is the warning lamp and this wire should be connected to the single this cable that comes from the black multiplug on the specialTauto alternator.

The B+ wires (Battery Positive!) are the 2 ring terminals that have about 4 brown wires on each.

The L wire (Lamp !) is usually brown/ yellow. This may have aged and appears white (possibility ?)

The other cable is not required as was used for the old alternator. Tape this up or better still put an insulated end crimp on (using ratchet crimpers :wink: ) and tie it out of the way.

If the L (lamp) wire is not connected then the alternator will not produce a charge.

DO NOT connect your white wire and the red wire together. I would guess that your white wire is the waring lamp and the red wire is the 12v ignition feed that isn't required. Obviously do the tests I mentioned earlier.

Hope this helps,

NickT

[Outatime]

Thanks Mike and NickT!!!

All sorted and running now, constantly at 14.2V even at 3000rpm

I am happy!!! :lol:

[NickT]

(Moved to Electrical section - no worries )

Which wire was the warning lamp then john ?

Glad it is sorted.

NickT

[Outatime]

The L wire was the white one, just as you predicted!

[NickT]

Outatime Wrote:The L wire was the white one, just as you predicted!

:wink: