Case IH 885XL Charging System

[gadzooks]

Can't seem to keep the battery charged, even though once started the battery volts are going up quite a bit higher than the battery's resting voltage.

Battery itself seems ok, it'll charge fine on the wall charger then hold a good voltage for days left by itself off the tractor.

Not sure if it's not charging properly or if something's flattening the battery over a few days.

Just beginning to poke around with a multimeter but haven't got much in the way of info on the system.. does anyone know stuff like whether it's an alternator with a builtin regulator, or one with a remote regulator? electromechanical or solid state? where to find wiring / circuit diagrams, parts layout etc..

 

[Wisconsonian]

Almost certainly a solid state internal regulator. If you get the voltage up to about 14v running, then it's charging fine. Check the voltage again before you shut it off, alternators can fail as they warm up, then charge again after they've cooled off.

If the battery holds a charge on it's own for days, but dies overnight on the tractor, I'd suspect the alternator is leaking back, usually there's nothing else to leak on that age of tractor. Check the amp draw with everything shut off, and then disconnect the alternator wires and check the amp draw again. A test light between the battery and the cable works for this usually. Or a multimeter on ohms or milli amps.

 

[Richard Devon]

This is the wiring diagram for the 95 series, more or less the same as the 85 series

 

[gadzooks]

Thanks, should be able to pick my way through it with the meter now. Much appreciated.

 

[X344chap]

Lucas 18acr 45 amp alternator - about £65 or you can replace the regulator and rectifier for £17.

 

[milkloss]

I would consider a new battery before going too mad on it. Recently had similar with our 885 and despite he battery appearing to be good it just didn’t have enough guts for a good start. Tried changing he starter etc too

 

[gadzooks]

Turned out to be alternator leaking back & battery + terminal gone bad.

The cable was inside the battery terminal's bore, but the bore had somehow widened and the conductor was floppy in there giving rise to intermittent high resistance. Packed it out with extra pieces of 2.5mm twin and earth conductor & then soldered the hell out of it. Without the packing wire the solder was just falling straight out.

Changed the alternator (Lucas A127 12V right-hand) & bobs yer uncle.