I worked on this lil cat today and lever on the injector pump was coming off and bolt holding it on was bent so i took it off cleaned it up and put a new bolt in it....solenoid pulls to shut machine off instead of pulling to make it run which is strange to me usually its the other way around. Took the solenoid off and put 24 volts to it and it pulls fine. So what i need to know is what puts power to it in order to shut it off when turning the key off? I figure something puts 24v to it for just a few seconds and shuts off otherwise it would drain the batteries. Anybody know where i need to check. Its a 96 or 97 model excavator ser# 7DK03907. Thanks.
Anyone? Anyone?....:beatsme
7DK is not coming up in SIS but that 312 has a panel behind the cab. There is a fuse and a relay that will power the shut off solenoid. Having a hard time determining which relay and which fuse it is in the schematic. Try ohm -ing from the wires at solenoid and finding the fuse and relay for that circuit. The Controller is what sends the signal to the relay to excite the solenoid.
7DK not coming up for me either. For a 312 the nearest prefix I could find was 6GK. Schematic shows a shutdown relay that is connected to the shutdown solenoid via a Pink wire #327. The other wire on the shutdown solenoid is a 200 black which is connected to ground. The shutdown relay 9X-8124 is located in the relay panel. There should be 3 wires to it. 109 orange (connected to terminal JJ) that is permanently live when the master switch is closed, 332 Blue (connected to terminal L - coil) that goes to the engine control unit, and the same 327 Pink wire (connected to terminal JJ) taking 24V to the shutdown solenoid. There should also be a 109 Orange jumper between terminal JJ and another terminal on the unit that has no reference. As I see it the engine/pump control will open to wire 332 Blue thus energizing the coil. That will pull the main contacts in and send 24V from input wire 109 Orange to 327 Pink and thus activate the shutdown solenoid. If you want a copy of the electrical schematic send me a PM with an e-mail address but please check the machine Serial Number first.
Thanks for the responses . i did check the serial # on the data plate inside the cab and it says 7DK.... but its ok i put the solenoid back on and cleaned the connection. Tried it and it worked fine. I believe the shut off lever on the pump was the problem after all. After i fixed that turned out the alternator wasnt charging either so changed it out too..that sucker was over $400!! Glad i dont have to pay for it...lol. Thanks again. Now the A/C isnt working right either but i think its the head unit cause its lit up but you push any of the buttons and it does nothing. It was blowing when i first worked on the machine but i turned it off and now it wont come back on...anyway. Id take any input on that too.
Glad you got it working properly. In 2006 I was looking at used excavators and I tried a 312 with 7DK serial number. I just looked at my buyer information guide on Cat Equipment and they have 6GK and 7DK both made from 1992 to 1996 with identical specs and both machines made in Japan. There were more 7DK series made than the 6GK series. The 312 7DK seemed like a good machine when I tried it but I ended up with a Hitachi EX120 which has been very good. The Hitachi had a hydraulic thumb and the Cat didn't, that's what made the difference. FWD FWD