Electrical issues

[Petierla]

Hi, Hope someone can help me. I lent my 743 to a mate (first mistake). When it returned he told me he had left the ignition on for a week or so and had to jump start it. Now it will not charge over 11.5 volts. I had a bit of a poke around and found the wires running from the alternator to the cab loom and the alternator to the starter motor were burnt so replaced them. Tested the alternator with the starter cable removed and it charges at 14.5 but as soon as I hook it back up the charge drops back to 11.5. Big thanks for running this forum.

 

[OldMachinist]

Likely burned the diode out in the alternator if it's the newer style. You can download the electrical section of the service 743 service manual here http://www.mediafire.com/?wk8boxnybvnkc and check it.

 

[skidsteer.ca]

Likely burned the diode out in the alternator if it's the newer style. You can download the electrical section of the service 743 service manual here http://www.mediafire.com/?wk8boxnybvnkc and check it.

You did recharge the battery fully? Where are the battery voltage reading at when the unit has sat for 24 hours?
Ken

 

[frogfarmer]

You did recharge the battery fully? Where are the battery voltage reading at when the unit has sat for 24 hours?
Ken

Like Ken said make sure the batt is fully charged and holds at least over night. The alt was not designed to charge a completely discharged batt although many have and survived. The wiring may be an indicator to a long standing batt problem but a machine that age usually has some wiring damage or repair.

 

[Petierla]

Like Ken said make sure the batt is fully charged and holds at least over night. The alt was not designed to charge a completely discharged batt although many have and survived. The wiring may be an indicator to a long standing batt problem but a machine that age usually has some wiring damage or repair.

Thanks for the quick replies. Yep, I was trying to charge the battery from dead flat. I took the battery out and stuck it on the charger instead of letting the alternator do all the work, problem seems to be solved. You guys have earned yourselves beers and a barbie if ever in Victoria, Australia. Many Thanks!