Alternator and regulator question - Siromer 304 / Jinma 254

[aesmith]

Hi,

Our tractor seems to be charging only very slowly, for example a couple of minutes after engine start the battery voltage is still only 12.5 volts and very slowly creeping up. Before doing anything too drastic I'd like to understand how it's supposed to work. According to the diagram there's what looks like a normal sort of alternator output cable which should go to the ammeter on the load side. Then there's the regulator that has one connection to switched live, 12V when the ignition switch is ON, and two lines to the alternator. Does that sound correct? In the first place I'm going to check the connections and make sure there's not just a dirty connector causing the problem.

If it's not that easy, is there a recommended after market alternator that will fit without too much trouble?

Thanks, Tony S

 

[aesmith]

Quick question - in the standard setup does the alternator or regulator rely on current from the charge warning light to trigger it? Asking because there's a blown bulb in one of the panel indicator lights. I can't see any reference to this in any of the circuit diagrams so may be a complete red herring.

 

[RonMar]

I dont think it really needs that light, the reg simply completes a circuit to ground to light the lamp if it is not meeting rated output.

I think most of these alternators have always been pretty anemic, they were only rated at 15A anyway. Your slow voltage rise could also be a factor of a discharged battery. Try an external charger and fully charge the battery then see what the alternator floats up to with a charged battery.

Mine has never delivered what I would call an acceptable vehicle charge voltage(14.5V +/- 0.5V). Mine only ever reaches the mid 13V level which I would call closer to a long term float charge. Unless you run long hours your battery is most likley never getting fully charged.

The regulator does receive power via the 10A chg fuse and I believe it also senses that voltage to regulate to. I have contemplated adding a diode to that circuit which would lower the voltage to the regulator 0.5V and should cause it to up the alternator output by that much but I havnt got around to it. I put a maintenance charger on the battery at least twice a year to maintain a reasonable state of charge on the battery especially in the winter. Mine is a 2005 model with 650ish hours, and I am still running the original chinese battery(that might be some kind of record). I finally had to jump start it this winter for the first time, but I also neglected to use the battery charger this winter... it is stored under a woodshed roof but not “indoors” and I use a plug-in coolant heater to warm it before a cold start, so my cranks are not lengthy...

There was a gentelman who put an engine from a 254 into a Mazda pickup. If I recall correctly he said a Mazda B2000 alt was prettymuch a direct bolt-in. 60A I think and internally regulated, dont remember the year range, you should be able to search this chinese forum for his postings...

 

[aesmith]

I dont think it really needs that light, the reg simply completes a circuit to ground to light the lamp if it is not meeting rated output.

Cheers. Having another look I think the warning light may be completely unrelated. There are four connections on the alternator, one is the main output, two to the regulator and presume the fourth must be for the rev counter. If that's the case, and I still need to check properly by following wires, I suspect the warning light is simply an "On" indicator with no connection to the alternator at all. I don't ever remember seeing it lit.

So I've decided on a two pronged attack here - firstly try a replacement voltage regulator, they're dirt cheap but will take a while to arrive. Meanwhile I can borrow the alternator off our digger (backhoe) to see how difficult that would be to fit, with a long term view being to replace the original alternator with a normal A127 or similar internally regulated unit.

 

[RonMar]

Well the indicator should be lit when the engine isn't running. my alt and oil lights illuminate whenever key is on and engine is not running.

There is no tach sense in the alternator. Tach input comes from a sensor on the left side of the bell housing sensing the ring gear teeth on the flywheel.

Here is a link to a schematic I drew many years back for my 2005 Jinma 284.

https://www.tractorbynet.com/forums...28-jinma-284-electrical-schematic-2005-a.html

 

[aesmith]

Thanks again especially for the diagram. I'm a bit puzzled about a connection from voltage regulator to flasher relay, is that just a way of grounding that circuit? On my tractor I don't any warning lamps other than the Green one with the blown bulb. The user manual make reference to a Green "Power On" lamp, although they show it in a different position. More wire tracing needed I think, and I'll fix that green light while I'm at it.

 

[RonMar]

I dont know why that connection between flasher and reg is there either... You could be right, it could be a pathway to ground.

 

[TimP82]

Two years ago, I replaced the OEM alternator/regulator with a single wire GM self exiting alternator, that puts out 60 amps, for only $60. I have been running this alternator for a couple of years now and haven't looked back! It took a lot of research at the time to find out what to upgrade to but this was the simplest one and I wanted to upgrade it and eliminate the need for an external regulator. I just had to get a different length belt also. That was easy enough to find at my local Tractor Supply for I think $6. Go to dbelectrical.com and search this: Alternator 1 Wire Universal Self-Excited 10SI 10 SI 7127-SE. I tried posting the link but I do not have permission because I have not met the required 3 posts in order to do so.

 

[ymurf]

Two years ago, I replaced the OEM alternator/regulator with a single wire GM self exiting alternator, that puts out 60 amps, for only $60. I have been running this alternator for a couple of years now and haven't looked back! It took a lot of research at the time to find out what to upgrade to but this was the simplest one and I wanted to upgrade it and eliminate the need for an external regulator. I just had to get a different length belt also. That was easy enough to find at my local Tractor Supply for I think $6. Go to dbelectrical.com and search this: Alternator 1 Wire Universal Self-Excited 10SI 10 SI 7127-SE. I tried posting the link but I do not have permission because I have not met the required 3 posts in order to do so.

I know this is an old post but how exactly do you wire this up? My farm Pro 2425 hasnt charged in years.

 

[Bob Rooks]

I know this is an old post but how exactly do you wire this up? My farm Pro 2425 hasnt charged in years.

This is the alternator from the link that Tim posted. It should be noted that you will have to get a smaller pulley to compensate for the slower engine speed.

Alternator for Universal Self-Excited 10SI, 7127-3SE, 7127SE, 400-12449; ADR0152

Shop for the Alternator For Universal Self-Excited 10SI, 7127-3SE, 7127SE, 400-12449; ADR0152 at DB Electrical. The best selection, low prices, fast shipping, and great customer service.

www.dbelectrical.com