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power wire to hour meter gone, how do I connect power to meter

L

lake side bob

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Oct 2, 2009
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Location
minnesota
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owner operator
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.
 
Tyler d4c

Tyler d4c

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Salix Pa
That green wire goes to the r terminal on the alternator. If someone installed a cheapo replacement it may not have a r terminal.
 
Tugger2

Tugger2

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British Columbia
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?
 
Tyler d4c

Tyler d4c

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Tugger2 said:
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?
Click to expand...
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
 
L

lake side bob

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Oct 2, 2009
Messages
252
Location
minnesota
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owner operator
Nige said:
According to the electrical schematic the wire feeding the service hour meter is #403 Green and comes off the P terminal of the alternator.

View attachment 258554
Click to expand...
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
 

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  • Cat d3c alternator 001.jpg
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Tyler d4c

Tyler d4c

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lake side bob said:
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
Click to expand...
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.
 
Nige

Nige

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lake side bob said:
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
Click to expand...
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..........
 
L

lake side bob

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minnesota
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owner operator
Nige said:
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..........
Click to expand...
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.
 
Nige

Nige

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lake side bob said:
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.
Click to expand...
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.
 
R

Richard V

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Quebec
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 ?
 
Nige

Nige

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Richard V said:
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 ?
Click to expand...
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.?
 
R

Richard V

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Location
Quebec
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.
 
kshansen

kshansen

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Nige said:
It may only have 2k hours on it but it's 20 years old...........
Click to expand...
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!
 
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