Cat D4g electric issue

[CenterlineShop]

My 02 D4g just started this problem. Operating the other day, electrical light came on but I did not have any problems with the function of the machine. Starts fine and lights work. Started this morning, no light, moved the machine about 30 ft and the light came back on. I have had problems in the past and still with oil pressure gauge topped out, same as fuel gauge but have had no problems in performance. I will be testing voltage this morning, just wondering if anyone has had issues like this with the same model of machine. Thanks as always.

 

[Nige]

Is this the same one as before..? Do you have the electrical schematic..?

 

[BladeManBob]

Nige,
Are the wiring schematics you refer to in the parts book or service manual?

The schematics I see in my D4G parts book are a little hard to read. And the entire book is in black and white.

 

[Nige]

A fold-out large size paper version of the Electrical Schematic is meant to be part of the Service Manual but they often disappear.

 

[BladeManBob]

I wonder if it's included with the CDROM/DVD copy that may be several hundred dollars cheaper than the print version?

 

[Nige]

The print versions and the CD contain the same documentation afaik.
I sent you a message.....

 

[CenterlineShop]

Update...thanks guys for your posts. Nige, yes it is the same dozer. Little by little, I am resurrecting this machine. At some point I will need to replace her. I unplugged the alternator...light went out, plugged it back in and no light. Checked the charge and I was getting about 14.8 volts. I moved the machine again and the light came back on. I had a job that had to be done and ran the machine with the light on, assuming that it was not charging. I have the electrical diagram but I am thinking about having it printed in an engineering plan size as working off of the computer proves to be rather problematic. Do you guys have any thoughts about having the alternator rebuilt or buy one from Caterpillar if this ends up being the problem. Again, I thank you guys for your input and assistance. Erik