wiring a non-spec alternator to 1gm10.

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niallw

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Last season after some issues decided to remove and overhaul my 1gm10. Very stupidly I did not pay attention to which cable went to which pin on my alternator. I did take some photos but Ive found these unhelpful for reconnection.

Having looked at quite a few other threads on this subject came across links to these PDF documents. Having looked at both of these Ive decided I must have a different type of alternator (maybe auto, dont know) to the schematic diagrams given in the PDF's.

hitachi 35A workshop manual (PDF)

hitachi 55A workshop manual (PDF)

There is no identifying words, branding on my alternator apart from following numbers;
2005 08 124
This is presumably a date/batch no, so none the wiser there.

If you check my pictures on the link, you will see the rear of alternator with 4 pins and a 3 pin socket. I know the plug going into socket has only 2 cables from it, one to charge lamp on panel, other to...

http://www.flickr.com/photos/niallw/?saved=1

Having reconnected my starter and soleniod there is only a red and a black cable to connect to alt., trouble is there is a possible four pins to connect to.

I had thought I'd be able to turn the alt enough by hand to be able to work out the which are the regulated output pins using the DC voltage setting on my MM, but this hasent worked. Does anyone know of any way i can define which are the reg output pins and polarity.

There are some further clues, if you look closely at pictures you should see lettering embossed into the casing at rear of alt (close to the 3 pin socket).
E - presume for earth
F - field ??
N - neutral or negative ??
 
No, sorry it isnt obvious. If it was I wouldn't be asking forum!

My alternator gives no indication about which is the Battery (positive) regulated output.

I suspect this is NOT a Hitachi alternator but dont know make as there is no brand name/symbol.

Id be grateful who can identify the type/make so as i can try to get relevant schematic diagram. Check photo's on;

http://www.flickr.com/photos/niallw/?saved=1

Ignore the cow pictures... thats my wife's doings... dont ask!
 
Yes I have found it now, I think

As pvb says a Nippon Denso

Either of the insulated studs on the RHS can be the battery connection.

The external regulator plugs in to connect with the three blades at the top. I think E is the negative (earth) connection, F the supply to the field via one brush ( the other brush is earthed) and N must be the output to the regulator.

Should be easy enough to confirm. ( by taking the cover off if necessary)
 
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No idea what make this is.

Looking at the picture, however, I would think that the main + output terminal (for your heavy charging cable fitted with a ring terminal) is one of the bottom two studs. It will be insulated from the metal body: this should be visible, but a check with a multimeter set to a low ohms range should confirm. The other stud should be connected to the body; it can be used as the main - terminal, but it is more common to use the engine metalwork so no connection. (It is less common, but possible, that the - terminal is insulated from the body; again this can be checked with an ohmmeter. If this is the case look for markings stamped into the body to identify which is which or look at the colour of the insulation: one red and one black would be helpful. In this case there will certainly also be a heavy - cable looking for a home.)

That leaves the 3 auxiliary terminals E, F and N. I was going to compare them with VicS's handy diagram, but the post with that seems to have disappeared (how could that have happened?). Anyway, assuming you don't have an external regulator (you don't, do you?) then two of them will be the field (connects to the warning light) and the sense terminal for the regulator (connects to the "ignition" switch), respectively. The third connection is likely to be for the tachometer. (If you have a tachometer then that would support this, if not it may be left unconnected. If this is the case you should only have two auxiliary cables to connect: does one of the terminals lack connection scratch marks?) If you don't have a tacho but do have three wires to connect then it gets harder ...

The ohmmeter can be used to find the regulator sense connection: its resistance to the - terminal will be much higher than either of the other two. (If all 3 are low then you probably have an external regulator, and we're getting into difficulties.) Telling the other two apart is harder. I think (without having the circuit in front of me) that measuring (both ways round to allow for the diodes) between the + terminal and each of the unknowns will give higher resistance values for the field terminal than for the tacho. If this is the terminal labelled F then that would be a good confirmation.

(I have seen a table listing terminal designations for a range of alternators but I can't remember where. Googling alternator connections produced more results than I cared to wade through.)

Unless they're labelled, you presumably will have the same problem identifying your wire connections, but again an ohmmeter test should confirm what's on the other end.

Oh, I really wish this forum would let you see new posts made since you started typing!
 
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DaveS said:
No idea what make this is.

Looking at the picture, however, I would think that the main + output terminal (for your heavy charging cable fitted with a ring terminal) is one of the bottom two studs. It will be insulated from the metal body: this should be visible, but a check with a multimeter set to a low ohms range should confirm. The other stud should be connected to the body; it can be used as the main - terminal, but it is more common to use the engine metalwork so no connection. (It is less common, but possible, that the - terminal is insulated from the body; again this can be checked with an ohmmeter. If this is the case look for markings stamped into the body to identify which is which or look at the colour of the insulation: one red and one black would be helpful. In this case there will certainly also be a heavy - cable looking for a home.)

That leaves the 3 auxiliary terminals E, F and N. I was going to compare them with VicS's handy diagram, but the post with that seems to have disappeared (how could that have happened?). Anyway, assuming you don't have an external regulator (you don't, do you?) then two of them will be the field (connects to the warning light) and the sense terminal for the regulator (connects to the "ignition" switch), respectively. The third connection is likely to be for the tachometer. (If you have a tachometer then that would support this, if not it may be left unconnected. If this is the case you should only have two auxiliary cables to connect: does one of the terminals lack connection scratch marks?) If you don't have a tacho but do have three wires to connect then it gets harder ...

The ohmmeter can be used to find the regulator sense connection: its resistance to the - terminal will be much higher than either of the other two. (If all 3 are low then you probably have an external regulator, and we're getting into difficulties.) Telling the other two apart is harder. I think (without having the circuit in front of me) that measuring (both ways round to allow for the diodes) between the + terminal and each of the unknowns will give higher resistance values for the field terminal than for the tacho. If this is the terminal labelled F then that would be a good confirmation.
Click to expand...

Thanks to all the responses. DaveS makes a point about looking for pins that are insulated. Two of the pins (on RHS of picture) do have insulating washers. The upper one I think is unused as it has some corrosion on the nut.

I dont think I have an external regulator, certainly there is nothing obvious but I will look agian next time at boat (Monday). Ofcourse your thinking the best way would be to take alternator apart to look for regulator circuitry, Ive tried this, managed after lot of effort to remove the 3 (philips head) bolts holding case together but still could not separate the casing.

I'm resigned to taking alt to an auto-electrician, hopefully they can definitively label pins on alt, and hopefully tell me nominal output amps.

I will post on thread again, hopefully with some results.

By the way DaveS, your location W Scotland, anywhere near Barcaldine? PM me if you like.
 
mitiempo said:
That is where I got it - I have it on my computer in pdf.
Click to expand...

Thanks mitiempo/ VicS, this does make sense. To be honest had'nt even noticed about the insulating washers before i started thread.(how to get embarrased smillie?)

The male plug going to the EFN socket has only two cables coming from it, i will try following these to look for a regulator.

Following your logic the two LH pins may also be same connection for my negative batt connection.
 
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