Caterpillar D3C serial number 6PF00231 The hour meter stopped working. took dash apart after some time discovered there is no power in the green wire that the red wire from the meter plugs into and is connected to the positive terminal on the hour meter. I tried connecting a wire from hour meter to other hot wires in dash, lights, amp, voltage the hour meter works when it has power. As the power wire to the hour meter is inside a wire weave and I can not follow it to where it connects to a power source; can some one communicate how I can wire the hour meter to power, so it is powered only when the engine is running. [Not] when the master switch is turned to on position, because that's left on after the governor control lever shuts off fuel all the time. I can run or route a separate wire from anywhere to the hour meter to power it. I looked for a fuse box to see if there is a separate fuse for the hour meter, can not locate a fuse box, does the dozer have one, if yes where is it located? I really want the hour meter to only record hours when the engine is operating, the problem I am having is the power sources in the dash have the hour meter recording time with the master switch turned on with the engine running or not running, and with the master switch turned off certain power sources still power the hour meter. Your input is greatly appreciated.
That green wire goes to the r terminal on the alternator. If someone installed a cheapo replacement it may not have a r terminal.
The hour meter supply comes from the engine oil pressure switch. Sent you a PM.
Must be different then the 3 I had talk about assuming.......
303CCR s/n BXT02093 I have a similar problem , my excavator hour meter has quit . Is the oil pressure sending unit the place to start looking on these?
My 303cr that's a model older then your 303ccr uses the r terminal for the meter id venture a guess that yours is the same as they use the same engin
According to the electrical schematic the wire feeding the service hour meter is #403 Green and comes off the P terminal of the alternator.
Thank you I will look at it. Bob
Nige The alternator on this D3C dozer only has two options to connect a wire to, one is the battery the other is always hot, engine off it is hot, engine running it is hot. see attached. The drawing is what is on the alternator. The cap on top of the alternator held on by two screws I did not take off, tried and started to strip the screw so I stopped. any suggestions? Bob
The green wire to the n terminal is referring to tuggers 303ccr excavator. Your d3c hour meter runs off a oil pressure switch as stated in Niges first reply. Apologies for getting your thread off topic.
Use the SENR3812 electrical schematic I sent to you. That ought to help. It shows the connection to the service meter (hourmeter) coming from the oil pressure switch. Ignore the bit about the alternator, that's for a different machine altogether. It's hard to keep threads on track when we start talking about multiple different machine models..........
Nige Why can i not just wire the hour meter to the power to the engine oil pressure gauge, my understanding the power to the oil gauge comes from the oil pressure switch same as the hour meter so I am thinking take power from the engine oil pressure gauge to power the hour meter also. it would only record hour usage when the engine is operating. Comments.
Sorry you can't do that. The signal to the oil pressure gauge from the oil pressure sending unit is a variable one (clue - that's what makes the needle move). It is not a fixed voltage like the one that comes from the oil pressure switch. The switch is simple, below a certain oil pressure it is open = no voltage. Above that same pressure it closes = voltage. That is what you want to energize (or not as the case may be) the hourmeter all the time the engine has positive oil pressure Locate the engine oil pressure switch on the side of the engine just above the starter. Identify the light green wire coming off the switch (the other one is orange) and run a duplicate wire from there to the hourmeter. I'm going to go out on a limb here and say that very probably your backup alarm doesn't work in addition to the non-functioning hourmeter.
I have the same problem , the service meter on a 308C KCX00519 is not working but the feed comes from the L terminal of the alternator. Any ideas ?
Have you checked for continuity on the K776 Green wire between the alternator L terminal and the hour meter.? It goes through at least one major harness connector. What about the connection from the hour meter to ground.?
Thanks Nige, yes I checked I do have 28 volts +/- on the 2 pins connector when the machine is running. I was surprised the service meter is dead as it only show 2,200 some hours. I will replace it.
It may only have 2k hours on it but it's 20 years old...........
good point !
How about temporally hooking some wires to that meter say over night and then see what it reads in the morning? If it is 20 years old who knows how many times that meter might have been replaced!
On my 308C CR, the power comes from the L terminal of the alternator.