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John Oliver
John Oliver,
Category: Construction and Road Equipment
Satisfied Customers: 201
Experience:  manager at White Eagle Ag and Truck Services
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I have a 2002 deere 250skidsteer. The problem is alternator

Customer Question

Hi, I have a 2002 john deere 250skidsteer . The problem is alternator not charging and no exterior lights. I tested the battery and it's ok. I took out the alternator, had it checked and it's ok..I jumped the d+ post on the alternator and it started charging. I tested the wire to the d+ post! it is not live. It goes into a connector that has 2 wires coming to it. They are not live..they are yellow with red spots and the other is brown with blue spots..I checked the fuses, they look ok..I also replaced the ignition switch, but nothing has changed.
JA: We'll do all we can to help. Is there anything else important you think the Heavy Equipment Mechanic should know?
Customer: No..
Submitted: 1 year ago.
Category: Construction and Road Equipment
Expert:  John Oliver replied 1 year ago.

good afternoon my name is ***** ***** I can help you. have you checked the diode that is connected to the alternator with an ohm meter?

Customer: replied 1 year ago.
I took the alternator off and took to a starter and alternator shop, who checked it and said it was fine. He suggested jumping 12 volts to the d+ terminal and it worked??it started charging
Expert:  John Oliver replied 1 year ago.

awesome but did you test the external diode? its connected to the alternator wrapped in a black plastic cover. 3 wire

Customer: replied 1 year ago.
I tested the 2 wires that go to the connector(the black plastic cover) and the 2 wires coming in have no power
Expert:  John Oliver replied 1 year ago.

so the 452 yellow wire has no power correct?

Customer: replied 1 year ago.
All three don't have any power
Expert:  John Oliver replied 1 year ago.

I suggest testing the F1 fuse

the K4 accessory relay

swap relay with one next to it and retest

Customer: replied 1 year ago.
I looked at all 4 fuses and they all look ok...
Expert:  John Oliver replied 1 year ago.

and the relay??

Customer: replied 1 year ago.
What do you mean by a relay? What does it look like? Located?
Expert:  John Oliver replied 1 year ago.

test for 12 volt at the key switch wire 550 (yellow/white)

pin 30 on K4 relay wire 445 yellow 12 volt power. the relays are next to the fuse block (lift the cab) and you should see them

Expert:  John Oliver replied 1 year ago.

k4 is the relay furthest back of the 3 to the rear of the machine. k1 being the one closest to the front. relay is a small square box looking part

Customer: replied 1 year ago.
I'll go look..will write you back later..I have someone coming over later with a multi tester.. How late can I write to you?
Expert:  John Oliver replied 1 year ago.

test light only. you need resistance on the circuit for a good reading and multi testers don't offer that

I'm here for a couple more hours

Customer: replied 1 year ago.
Will write you back on Monday? Thank you tom
Expert:  John Oliver replied 1 year ago.

sounds good!

Customer: replied 1 year ago.
Hi john, Can we follow up from last week about my john deer 250 skidsteer.? I checked k4, it has power to one post and I noticed when I plugged it back in , I heard a click. I checked k1 and it had no power going to it. I did not check the middle one.
Expert:  John Oliver replied 1 year ago.

was it pin 30 that had power on K4?

did you test wire 550 at the key switch?

Customer: replied 1 year ago.
I'm gonna check..I'll write back to you..
Expert:  John Oliver replied 1 year ago.

how did you make out?