5570 charging system

IH4739 · Jan 11, 2017

Does the 5570 have the voltage regulator built in to the alternator? I am having some charging trouble and was trying to eliminate all possible causes.

RNeumann · Jan 11, 2017

Don't know but it's about a 3' test to find out-

Remove positive cable from alternator with a known good and charged battery-

Start tractor

Hook volt meter to positive of alternator and ground

Change RPMs and see if voltage changes

If voltage changes and goes over about 14.5v it isn't. It should be way more obvious if it isn't though.

Most (not all) today are internally regulated. If it has a couple smaller wires going to it those are typically used to excite it and or read voltage for the computer and gauges/idiot lights.

I've seen people on here swear the electrical is not a battery cable. Then go round and round for days struggling on to find it was indeed a battery cable. Verify those as part of your diagnosis.

IH4739 · Jan 11, 2017

Thanks for the info. I checked the voltage at positive stud on the alternator while it was running but did not disconnect the cable though. I will try that tomorrow. Sometimes it will read over 14 volts while running and today it would never go over 11.90 volts.

RNeumann · Jan 11, 2017

11.90 volts is just battery voltage- it's not producing power today. Check the connections for the other wires going into the alternator- it should be a plug. Make sure those are all making good contact and the plug is in good shape.

If you have a fine probe or can read the wires going to the alternator. Verify at least one is showing battery voltage when running. The most common type alternator would be switched on or excited externally with this voltage.

Also watch the voltage at the alternator and play with the battery cables- especially the ground.

With a fully charged good battery you should be able to run for 30-60' or so (no headlights or other electrical draws). The biggest draw should be the fuel pump. I offer that as I don't know your situation- feed animals or push some snow.

RNeumann · Jan 12, 2017

Any luck?

IH4739 · Jan 18, 2017

Everything has checked out good so far, battery,cables,and alternator. It still will not make 14 volts to keep the battery charged. I am at a loss. May have to take it to a dealer .

RNeumann · Jan 18, 2017

It may be easier to remove the alternator and have a local auto parts store test it- most auto parts stores can test them. I assume it would take about 10' to remove which may be faster than hooking up your trailer and chaining it down.

IH4739 · Jan 19, 2017

I have already carried the alternator repair shop and it checked out fine

RNeumann · Jan 19, 2017

If it bench tests fine the only other thing it could be is the 12v needed to excite the alternator. For some reason the alternator is not getting "told" to turn on. With the tractor running and the plug to the alternator undone do you have voltage at the plug? If not make a jumper wire and provide 12v to it.
The only other complete outlier would be a bad ground connection at the alternator. Hook your meter to positive side of battery and make sure touching the back half of alternator shows voltage (it's grounded).