1456 Aternator, Voltage Regulator, Batteries ???

My 1456 has not been keeping batteries charged. As tractor is used mostly spring and fall for silage chopping, I put a battery charger to the batteries occasionally to keep them charged. The AMP light stayed lit when tractor was running. ( Kept switch off after tractor is running so AMP light not on continuously.) I had a guy check the alternator with a multi-tester and he said alternator was not working. Last week I installed a new alternator. Batteries were weak when I tried to start tractor but I charged them a while with charger and tractor then started. AMP light still stayed lit with tractor running with new alternator. Shut tractor off and decided to get new batteries to replace the five year old ones . Put in new batteries and engine started as it should with strong , charged batteries. However, the AMP light was still on. I took voltage regulator off and discovered that it was bad. Replaced it with a new one, reconnected ground on battery, turned on switch and AMP light did not light up as it should with switch on. I started engine and AMP light remained not lit. Each time in the last week when switch is turned on AMP light still will not light up. Yesterday, tractor starter would not turn over at all, it did not even click the solenoid. Batteries were dead. I took some from another tractor and started 1456, put batteries back on the other tractor and used 1456 without batteries and alternator wires unhooked all day chopping corn, leaving it to idle instead of shutting it off.

What to look for now?

The original system used an external regulator. the system is not as reliable and controlled as the internal regulated Delco SI10 series alternators.
Were it mine, I would use the newer Delco alternator with internal regulation.
The charge light can be used (See diagram) if the resistor and lamp are both good. The connection to terminal 4 of the existing regulator is disconnected and extended as needed to attach to the spade terminal #1 of the Delco. The #2 terminal of the new Delco is connected to the wire now connected to the #3 connection on the old regulator. Both of these can be with 14 gauge wire. The heavy wire on the original alternator's BAT terminal is connected to the new alternator's Bat terminal. The original regulator can be removed.
It is pretty simple. Jim

Your suggestion is well and good if one is starting from scratch to get a system to work. However, I have a NEW original style alternator, a new voltage regulator and two new batteries and I want to get these things to work. The systems on these old tractors worked well for me for years and I do not see any reason that they can not work for many more. I just need to know what else there is that may be causing the problem. Could it be the resistor in the porcelain block found mounted just above the voltage regulator? Years ago I found that one of them was bad on another tractor and batteries were not kept charged, but in that case the AMP light worked normally as it should have when switch was turned on and light went off as engine revved up.
I believe that I have a new resistor in stock and I will install it tomorrow to see what will happen.
Strange thing to me that AMP light is not working only since installing three new components . I guess that it could have burned out but what a coincidence doing when it did, if it did.
Perhaps one of the batteries has internal defect and has shorted out.

For starters I would unhook the two terminal connection at alternator. Then with a jumper ground the wire in that connector that goes to the field in alternator. If the lamp lights, which it should if all is good in regulator and wiring then your problem is in the alternator. If it does not light, check connections, bulb, resistor and lastly regulator. As you can see from the diagram Jim posted, the lamp feeds through the points in regulator to fields in alternator and this current flow excites the alternator. Once it starts charging, the relay closes, lamp goes out and current for alternator is fed through relay to regulator.

Both the resistor Shown, and the lamp filament must be good. Warning lights do go bad, and can cause charge failure. If you check the circuit with a continuity checker, or ohm meter, make sure to isolate the lamp from the circuit. Jim

The generic diagram is a good start but IH decided to do things just a bit different. Here is the actual diagram for your tractor.




If either the bulb or the resistor is burned out the system is still supposed to work. It must do so since IH used a flashing bulb that opened the circuit each time it flashed off.

One of the things they told us at the IH training session on electrical systems was if both the bulb and the resistor were burned out and you had to make it work without the correct parts, just move the #3 terminal wire to the #4 terminal.

Set your digital volt meter for ohms and see how many it pulls across the ballast resistor. If it's 0, it's open, which means it's bad.

The original resistor is 100 ohms. The replacement part is 25 ohms.

did you ever figure out what caused the Amp light not to come back on? I have the same problem with my 1456 with all new wiring, 10DN alternator, voltage regulator, resistor and new bulbs. However, with the Key ON and I unplug the light blue wire from the resistor the AMP light comes on.

(quoted from post at 23:54:04 11/16/14) did you ever figure out what caused the Amp light not to come back on? I have the same problem with my 1456 with all new wiring, 10DN alternator, voltage regulator, resistor and new bulbs. However, with the Key ON and I unplug the light blue wire from the resistor the AMP light comes on.

Click to expand...

Most likely the problem is the new resistor has too low resistance. The original resistor was 100 ohms. A replacement from a dealer is going to be 25 ohms. The change was made to get tractors with the 10SI alternator to start to charge a lower engine speed. Unfortunately making the same change with a 10DN alternator now means that more of the current to energize the rotor is going through the resistor and less through the bulb. Pulling the wire off the resistor causes all of the current to flow through the bulb.

Do you still have your old resistor? If you can't find a resistor with about 100 ohms to use in this application you could add resistors of lower value together in series to get near 100 ohms. A practical solution might be just to find a use resistor from another tractor that used the 10DN alternator.

Owen, you hit the nail in the head. I tried the easy thing first and cleaned up the old resistor and put it back on. Turned the key ON and the AMP light came right on. I then took 2 of the new resistors and hooked them in a series and the AMP light still wouldn't come on. I have a Fluke automatic selection tester and I checked the ohms between the 2 new resistors hooked up in a series and its only 3.0, while the old resistor is 10.0 on the display. The resistor sold to me over the CIH parts counter is nothing like the original ones. The tabs and mount hole is way too small and the porcelain casing itself is too small. I took it back and said there's no way that can be the new replacement. This is a gold demo Im restoring so I want it to be correct and original.