Hi all, I am new to this forum and going I can get some help. I have a John Deere 50D excavator which I bought recently. I have only owned it a few weeks and now have a bro lemme with the throttle. The SYS light is flashing red every half second and the engine is running at very high rpm and adjusting the throttle potentiometer does not slow or speed up the engine. I have tried a replacement potentiometer but this made no difference. Has anyone else had this problem?? Could it be a mechanical problem rather than electrical. All advice appreciated, hoping someone out there knows the answer.
Just disconnect the throttle linkage IF you have the mechanical injection pump..
How do I know, if mine is the mechanical one. There is an electric solenoid on the back of the pump, could this be the problem?
I run a 35d and had the same problem. For me it is a little electric motor that pulls a cable to control the throttle. For me the motor died and I was stuck on high idle. Deere wants 1200 dollars for that little motor with a little planetary gear on top of it and a cable. I have removed the cable and just use a bundgy cord to hold the throtle where I want it. I have found just the motor on Ebay for 10$ so I have one on order.
If your machine is done the same way as a 35d then follow the throttle cable to do this I had to tip up the cab and take off some of the sheet metal on the front left of the machine. Once you find the motor then there will be two sets of connectors on it one will have three wires I think and that tells the computer the orientation of the cable and the other will have two wires and it supply's power. Back probe into that connector and star the machine and see if there it power there. Turn the throttle control back and forth in the cab and see if it switches the polarity of the wires. But then doing this it will only work for a few seconds because when the machines sees something wrong with the system it will cut power to the electric motor. That's what I did to figure my problem out. Hope this helps.
Mine was doing this and the plug was loose under the cab, so if you hit a bump it would disconnect, sys light would flash and no throttle response.
Maybe this attachment will help.
And this.