Have a 311 Cat, sn 5pk00349 once in a great while, twice a year for a guess, I loose throttle and pump control, have to finish what I am doing with manual throttle control button behind armrest. when this is the case the machine can stall when you get into something requiring some pressure and the pump should change swash preventing stalling, but it doesn't. So yesterday with the key of machine starts making a loud clicking noise every 5 seconds, turns out this relay is being turned on and off every 5 seconds with the key off, when this is happening I have no throttle or pump control when i start machine and attempt to operate. It stops when I shut off the master switch. This relay feeds something else, because something else is also switching in the engine bay but no idea what.
So the relay in the picture is to control the shut down solenoid. Orange wires are power, Pink goes to power the shut down solenoid, and the blue is control from the pump controler, grounding to turn on the relay. Not sure yet if grounding enables fuel or shuts it off. Sounds like pump controller is having an issue. When I purchased the machine it came with 2 pump controllers, One in the machine owner had picked up used from another machine, and a spare that had been sent out to be repaired by an independant outfit but I was told was still junk after the owner had paid for it to be repaired. I had to change the used controller out of the machine for the "rebuilt" controller to get the machine to control pump swash and engine rpm. But this problem seems to arise when it rains. Cat Techline puts this machine as a gray market machine so they sent a schematic of a similar machine, 9LJ262 up. Don't understand how Caterpillar, one of the largest equipment manufacturers in the world doesn't have access to a schematic for a CAT machine because the serial number is "Gray Market" Did these machines have pump controler issues? And is there an outfit out there that rebuilds or repairs them?
The answer is quite simple. The machine was built for the Japan-only market and was never intended to be exported outside Japan. If such a machine ends up somewhere else in the world it was done outside any normal factory channels. Service information for these models is available but it's all in Japanese, including the electrical schematics. Having said that most differences between a grey market machine and the equivalent built in Europe or the US or wherever are generally related to sheet metal, cabs, etc. The mechanical/hydraulic guts of the machine will be pretty much the same. So the Electrical Schematic for 9LJ262-Up should be identical to your machine right down to the wire colours & numbers. Here's the document list for your machine. Original Parts manuals are available. Which one of the two listed will depend on whether your machine has an 8-port centre swivel or not. If it has the 8-port XJBP7202 is what you need, if not then you need XJBP7244 Regarding your question about the pump controller you need our friend from Sri Lanka to chime in. He's pretty knowledgable on them. However the fact that the problem occurs when it rains would appear to suggest that the issue is likely related to a electrical connection somewhere, or that water is somehow entering the controller.