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alternator wiring

Posted: Thu May 06, 2010 5:32 pm
by mickyd555
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I just want to confirm the wiring of the above alternator. I assumethe terminals are as follows:

B- Battery Positive
E- Exciter
N- Negative/Ground

then there is a small spade terminal marked L, there are two of these terminals and they are both the same (commen terminal). What do i connect this to? Do i have the above correct?

Posted: Thu May 06, 2010 6:11 pm
by DamTriton
"L" would be the lamp connection to the dash cluster. Generally other side of the actual lamp is connected to (switched) IGN +ve.

Look at the model and manufacturer of the alternator and give it a google, surprising what it turns up sometimes...

Posted: Thu May 06, 2010 7:22 pm
by mickyd555
DAMKIA wrote:"L" would be the lamp connection to the dash cluster. Generally other side of the actual lamp is connected to (switched) IGN +ve.

Look at the model and manufacturer of the alternator and give it a google, surprising what it turns up sometimes...

thanks mate, so what your saying is that the two "L" terminals get connected across the dash light? Keep in mind this is my 24V alternator (specifically for the winch) and wont be connected to the dash lights will i still need it other than for a warning light? Will it work without it?

Posted: Thu May 06, 2010 8:56 pm
by DamTriton
Do you know FOR SURE if the alternator has an internal regulator, as those other terminals may need to be connected to an external regulator??? (too may heavy cables for my liking in your picture...) Most internally regulated alternators only have 2 or 3 terminals in total, Batt (only heavy), Lamp, and sometimes a Voltage sense input.

IGN --------Lamp --------"L" (alternator)

Might be an issue to take lamp voltage from the IGN if your truck is currently running 12V.

May need to have a seperate switch coming from your 24V batteries and manually switch it on. Some alternators can use the "L" as excitation.

Posted: Fri May 07, 2010 7:45 am
by chimpboy
I share Damkia's concern, have a look here for common terminal layouts.

Yours, dunno, what is it off?

Posted: Fri May 07, 2010 8:42 am
by mickyd555
I hate Auto Electrics!!!!!

Ok, so i took the plastic cover off and took a photo. Is the white thing on the top the regulator? It looks like one!

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Posted: Fri May 07, 2010 10:06 am
by chimpboy
I guess so, it seems to make sense if it is a 28V/70A alternator.

I didn't notice you already said it was 24V, sorry. I've only ever dealt with 12V stuff so I can't really say. Is it a boat alternator originally or something? What brand is it?

Posted: Fri May 07, 2010 10:12 am
by mickyd555
chimpboy wrote:I guess so, it seems to make sense if it is a 28V/70A alternator.

What brand is it?
not sure on brand, its a universal one for machinery?

One of the "L" terminals is actually coming off the regulator though, what do i do with that?

Posted: Fri May 07, 2010 10:43 am
by chimpboy
mickyd555 wrote:
chimpboy wrote:I guess so, it seems to make sense if it is a 28V/70A alternator.

What brand is it?
not sure on brand, its a universal one for machinery?

One of the "L" terminals is actually coming off the regulator though, what do i do with that?
I would be guessing that that one is a lamp acting as an exciter, hence it needs to run to a lamp which then runs to the +24V side of your 24V battery set-up (switched to ignition, maybe with a relay). But it's a guess.

See the fact that it's universal might mean that there are some alternative ways of wiring it into different original systems. Maybe it has one L for one type of wiring and the other L for a different type. Or maybe it has dual outputs and the second L is to tell you there's a load on your second output.

Can you see if (say) N and E are separate or just one connection with two outputs? Anything like that?

I would personally probably take a punt on B -> +24V battery, N -> ground, and L -> a lamp, and cross my fingers, and leave the others unconnected. But this is risky so it's probably better not to do it :).

From a bit of googling, some other connectors that are common on 24V alternators, or marine/diesel alternators are "W" for a tacho output, AUX for an auxiliary battery output, IND or D+ for a signal terminal (basically the same as L I think?), F- for field control. There are even some with temp sensor outputs (usually for an external reg though). N and E are not common from what i can find.

Sorry, I wish I could help more.

BTW 24V/70A is a nice amount of power, you will be happy once you get it running.

Posted: Fri May 07, 2010 4:12 pm
by DamTriton
I would be guessing after a bit of research the the E terminal is the excitation diode output and should NOT be taken to earth.

Bosch diagram

There are some marine alternators that have BOTH external (normal mode) and internal (emergency mode) regulators to prevent frying electronics.

Posted: Fri May 07, 2010 7:05 pm
by mickyd555
DAMKIA wrote:I would be guessing after a bit of research the the E terminal is the excitation diode output and should NOT be taken to earth.

Bosch diagram

There are some marine alternators that have BOTH external (normal mode) and internal (emergency mode) regulators to prevent frying electronics.
thanks for the diagram, i might run a multi meter over a few thing in the morning to see if i can make sense. If not i might rip it back out and take it to an auto lecy to get some advice.

Posted: Fri May 07, 2010 7:54 pm
by chimpboy
Keep us posted, I would like to add whatever you discover to my alternator tech file :)

Posted: Fri May 07, 2010 8:13 pm
by mickyd555
chimpboy wrote:Keep us posted, I would like to add whatever you discover to my alternator tech file :)
will do :armsup:

Posted: Sat May 08, 2010 9:32 am
by DamTriton
This possibly gives you the answers to the markings plus a probable wiring layout. (scroll down a bit...)

Edit: the best bet would be to take it to a sparky and let them do the sussing out for you. 10 mins of their time versus us guessing with conflicting information coming from multiple sources over days for us to eventally be wrong anyway ("decision by comittee" is never the best decision or necessarily the right one)

Posted: Sat May 08, 2010 10:42 am
by chimpboy
DAMKIA wrote:This possibly gives you the answers to the markings plus a probable wiring layout. (scroll down a bit...)

Edit: the best bet would be to take it to a sparky and let them do the sussing out for you. 10 mins of their time versus us guessing with conflicting information coming from multiple sources over days for us to eventally be wrong anyway ("decision by comittee" is never the best decision or necessarily the right one)
For sure, especially a sparky who deals with the kind of machinery this alternator is made for.

Posted: Sun May 16, 2010 4:24 pm
by mickyd555
chimpboy wrote:Keep us posted, I would like to add whatever you discover to my alternator tech file :)
as promised (and i havent tried this yet but this is what they told me)

B - Battery +
E - Earth/Ground (once i looked closer its obvious as this terminal doesnt have an insulator from the frame to the stud)
N - 1/2 voltage (im this case 12V and not a huge allowable load, they said mostly taco's etc..)

Both "L" terminals go across a dash lamp which will also excite the alternator.

I am having trouble getting the right size belt so once i do i will test it out and confirm the above

Posted: Sun May 16, 2010 4:55 pm
by -Scott-
mickyd555 wrote:
chimpboy wrote:Keep us posted, I would like to add whatever you discover to my alternator tech file :)
as promised (and i havent tried this yet but this is what they told me)

B - Battery +
E - Earth/Ground (once i looked closer its obvious as this terminal doesnt have an insulator from the frame to the stud)
N - 1/2 voltage (im this case 12V and not a huge allowable load, they said mostly taco's etc..)

Both "L" terminals go across a dash lamp which will also excite the alternator.

I am having trouble getting the right size belt so once i do i will test it out and confirm the above
Who is "they"? The "N" terminal connection strikes me as nonsense. I'd go with the diagram in Damkia's link - N gets wired to the respective terminal on an appropriate regulator.

Without the correct regulator I would be inclined to leave it disconnected but well insulated - and see what happens. To me, it's effectively the neutral in a balanced 3 phase system, which means no current flow.

Posted: Sun May 16, 2010 5:38 pm
by mickyd555
-Scott- wrote:
mickyd555 wrote:
chimpboy wrote:Keep us posted, I would like to add whatever you discover to my alternator tech file :)
as promised (and i havent tried this yet but this is what they told me)

B - Battery +
E - Earth/Ground (once i looked closer its obvious as this terminal doesnt have an insulator from the frame to the stud)
N - 1/2 voltage (im this case 12V and not a huge allowable load, they said mostly taco's etc..)

Both "L" terminals go across a dash lamp which will also excite the alternator.

I am having trouble getting the right size belt so once i do i will test it out and confirm the above
Who is "they"? The "N" terminal connection strikes me as nonsense. I'd go with the diagram in Damkia's link - N gets wired to the respective terminal on an appropriate regulator.

Without the correct regulator I would be inclined to leave it disconnected but well insulated - and see what happens. To me, it's effectively the neutral in a balanced 3 phase system, which means no current flow.
"They" is an auto sparky. Which link are you talking about, i cant find the diagram which shows an "N"

Posted: Sun May 16, 2010 5:49 pm
by DamTriton
mickyd555 wrote:
-Scott- wrote:
mickyd555 wrote:
chimpboy wrote:Keep us posted, I would like to add whatever you discover to my alternator tech file :)
as promised (and i havent tried this yet but this is what they told me)

B - Battery +
E - Earth/Ground (once i looked closer its obvious as this terminal doesnt have an insulator from the frame to the stud)
N - 1/2 voltage (im this case 12V and not a huge allowable load, they said mostly taco's etc..)

Both "L" terminals go across a dash lamp which will also excite the alternator.

I am having trouble getting the right size belt so once i do i will test it out and confirm the above
Who is "they"? The "N" terminal connection strikes me as nonsense. I'd go with the diagram in Damkia's link - N gets wired to the respective terminal on an appropriate regulator.

Without the correct regulator I would be inclined to leave it disconnected but well insulated - and see what happens. To me, it's effectively the neutral in a balanced 3 phase system, which means no current flow.
"They" is an auto sparky. Which link are you talking about, i cant find the diagram which shows an "N"
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