Caterpillar 312C L Serial #CBA03413 This machine is operating to fast. All hydraulic functions are moving to fast Walking, Swing and and Digging. Now what I know that has happened. The monitor stopped working I repaired broken wire. Next time I used the excavator the monitor had stopped working again and it was operating at full speed with no hydraulic relief to the point of stalling the engine. I have found another dead wire at the monitor connection red to pink, but I can't Figure out where the pink wire is going. Any help please I have had repair men here they have no clue.
Has someone moved the override switch.? You want an electrical schematic to help identify wires.?
Good question I don't know where over ride switch is. Also I would like the electric schematic.
I'll send you a schematic. Keep an eye on your messages. Override switches are under the RH armrest. 21 turns override ON/OFF, 22 selects high/low engine RPM when switch 21 is in the ON position.
Thank Nige for the information the switches have not been moved. I think my problem is a relief valve or solenoid not opening a relief valve I will run down the wires from the monitor. First and thanks for your help.
I have found wire #169 pink from monitor is dead. Anyone know where it goes to, I think a relay but can't find it.
Look on Grid H-10 of the schematic on Page 8. 169-PK comes from the switched power side of the fuse box through a 5A fuse marked "Backup Monitor Cont".
Thank you. Nige I think my hydraulic problem is separate from the electrical side. My hoe does not have any pressure relief working. Is there a priority valve on this machine and where is it located. Also Thank you for all the information you have sent me.
I would suggest to first test the relief valve settings of the implement pilot system and the main hydraulic system (travel & implements). Record the pressures and report back. Don't go adjusting anything yet. Also make sure that the hydraulic oil is at nornmal operating temperature before you make any pressure tests.
Thanks Nige