pc200 -5

Went to move my exc. today to a new job and it wouldn't spin. You can see the house bump against the gears on the drive motor but when I move the lever to turn it just pulls the engine down and does nothing. Is there some valve that could not be releasing causing this. Also the throttle will only come up to about half throttle. It was working fine but it has been setting three or four weeks. I did change the starter while it was setting but this surely wouldn't have anything to do with these problems.

Have you checked the diodes on the throttle computer and the codes in the pump computer for problems? Here is a video that shows what to look for.

Thanks, I'll check those this weekend when I'm back around the machine.

I don't have anything flashing in either door. I'm guessing that not a good sign?

That would indicate that a fuse is blown. If I remember right they are on the right side console and it's the third one back from the rear. You will probably need to check them all anyway.

I checked all the fuses. It is this roll of fuses on the front right under the control panel near the floor right? That is the only fuses I found.

You are correct. I was thinking of a Dash 3 machine. I would suggest that you need to pull the panels of the whole console now and start checking wiring and connections.

Just went by the machine and started it. I have a red and green light on the bottom panel and nothing on the upper panel mirror.

Still a power problem. I'll check the red/green light fault when I get a chance. Is the green light flashing when the engine is running?

No it's solid. I'm going to get a mechanic to look at it. Computers and wiring are not something I'm very good at. I bet it's simple if the right knowledge is applied to it. I know the guy I got it from had some issues he fixed before I got it.

Attached is the list of possible codes and what they indicate. In your case no lights indicate no power to the pump control computer. The red green combination on lights indicate a problem in the throttle control motor, connectors or wiring to it. Let us know what you find.

Komatsu Dash 5 Fault Codes
Pump Control Computer
Code # Meaning
01 Short circuit in 2 stage relief solenoid system.
03 Short circuit in arm half flow solenoid system.
04 Short circuit in swing brake solenoid system.
05 Short circuit in travel speed solenoid system.
07 Short circuit in CO cancel solenoid system.
08 Short circuit in TVC solenoid system 1.
09 Short circuit in TVC solenoid system 2.
11 Disconnection in 2 stage relief solenoid system.
13 Disconnection in arm half flow solenoid system.
14 Disconnection in swing brake solenoid system.
15 Disconnection in travel speed solenoid system.
17 Disconnection in CO cancel solenoid system.
18 Disconnection in TVC solenoid system.
21 No 2 throttle signal system.
22 Throttle signal system.
23 Front pump pressure sensor system.
24 Rear pump pressure sensor system.
25 Pressure sensor power source system.
26 Engine speed sensor system.
28 Auto deceleration output system.
29 Overheat system
Dot Only Controller, red dot is between the numbers & is supposed to flash in time with engine RPM.
All Off Power source system.

Throttle Control Computer
Descriptors in bold indicate the light is on.
Condition
No lights show Abnormality in power source system or controller
Red Green Red Short circuit in governor motor
Red Green Red Disconnection in wiring harness of governor motor
Red Green Red Abnormality in governor potentiometer
Red Green Red Abnormality in fuel control dial
Red Green Red Abnormality in No 2 throttle signal

So as I comprehend this there are three lights. Could it be if the one computer has no power it doesn't signal the throttle control computer or am I trying to make this to simple.
Do you know which fuse powers the pump control computer? I'm guessing the the cover beside the fuse box gets into the wiring going to the computers. Is this right. Thanks,Gary

You are correct about the cover and the fuses. I think it is the third one counting from the back. I have had the carrier for the fuses get rusted out and no longer make contact. As I recall the fuse bar can be unbolted and you can test the wires directly past the fuses to see if the spring clips are any good. If you take off that panel you can see it all. You might find some places where rodents were feeding.

John, I appreciate all your effort helping me. This info will help a lot. I'm thinking it's something simple as it was running fine when I parked it. I hate a machine or truck that breaks just sitting. Again thanks, I'm going to it tomorrow with this info and see if I can do something.

Had the dealer come out. After a couple hours he found one wire corroded in the middle causing all the problems. Mechanic works on these older machines all the time so he is used to odd problems like this.