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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 2053
Experience:  Owner at DJ Wilson
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I have a caterpillar th460b and am having problems with it

Customer Question

I have a caterpillar th460b and am having problems with it not wanting to start. This machine was bought used at an auction. It ran fine the first 2 times i used it. Then in the middle of using it, it lost power. So, at this point, I have replaced the key switch. When i turn the switch, the dash comes on and a click is heard from behind the seat, i'm guessing it is a relay of some sort. When I turn the key to start, another click but it doesn't start. It will on occasion start right up, but that is very rarely. and if I turn it off it won't start again.
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Heavy Equipment Mechanic I'm going to connect you with knows all the tricks and shortcuts. Anything else you want the equipment mechanic to know before I connect you?
Customer: That is all
Submitted: 10 months ago.
Category: Medium and Heavy Trucks
Customer: replied 10 months ago.
I have 3 wires. An orange wire, which I believe is the starter wire. A Red wire, which I believe is the battery wire. and a yellow wire, which Seems to be the ignition wire that turns the dash and everything on so that it is ready to start. When I hook the red wire to the battery pole on the switch and the yellow to the ignition pole, it turns on and seems ready to go. With the orange wire on the starter pole, when I turn to key to start, nothing else happens. I hear a click behind the seat, but that is all.
Expert:  cat_engines_only replied 10 months ago.


This machine can be very difficult to troubleshoot without knowing the fault codes. The codes are best retrieved using the CAT ET software available to dealers. Some access can be done through the monitor. I will attach a file that shows how to view the codes with the monitor.

You said it lost power. Do you mean the engine died or stalled? Or did the transmission quit pulling? Did any warning lights come on? Are any still on now? Does the monitor have the service book icon next to the hour meter reading? Have you checked the starter solenoid wire for power when the keyswitch is in crank position? (White wire is the solenoid wire.) Did you check the battery cables on the starter for being loose? Have you tested the grounds on the engine and frame to the battery?

Please post the full machine serial number with your reply. It is the only way I can help you as these machines have multiple versions.

Customer: replied 10 months ago.
There was no attachment to this reply. The serial number is *****
Expert:  cat_engines_only replied 10 months ago.

I am sorry for the late reply. I have been without power for the past day and have just got everything back working.

I did miss the attachment, I will be below this post.

Customer: replied 10 months ago.
I have checked the voltage. It is 12v into the battery terminal on the switch. When the key is turned to on, the ignition terminal receives 12v and the dash comes on. When I turn the key to start, the start terminal receives 12v and nothing happens. no clicks or anything. I can't get the dash to go into the diagnostic mode.
Expert:  cat_engines_only replied 10 months ago.

Check for power from that keyswitch start wire (Orange wire marked 307) at the machine ECM. It is pin #1 of the J2 connector.

If it has power to this wire with the key switch in start position, place a jumper to the wire at pin #7 on the same J2 connector (Green wire marked 306) and try to start engine.

If nothing happens, go the the start relay (located on the back of the engine) and check for power to the 306 green wire at terminal #5 of the connector (relay post 86) when key switch is in start position. If it has power and it still does not crank, jump red wire to the white wire and see if engine cranks. (Red wire wire on relay must have battery voltage.)

If it still is not cranking, check starter connections. White wire marked 304 is to the starter relay and should engage starter.

Customer: replied 10 months ago.
I don't see any labels that indicate which connectors are which or pins for that matter. Do you have a diagram to help with that? I will check the voltage to the relay. Thanks!
Customer: replied 10 months ago.
Also, if the exclamation point is blinking on the dash, would that possibly stop the ecm from letting the engine crank? I can't get it to display the codes.
Customer: replied 10 months ago.
I found the diagram. Will remove the cover and test those pins this afternoon
Expert:  cat_engines_only replied 10 months ago.

Ok, Thanks for the update. I am only available at night as I work in the field during the day. If this is a problem I will OPT-OUT of this question.

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