Screwed this up TWICE......how to fix??

[Aquamoose]

A fix for this would be to install an electronic timer that provides a 12vdc output when the engine is running by sensing the voltage pickup.

As a disclaimer, I manufacture them for emergency vehicles but don’t want to be disrespectful by peddling my products here.

 

[Gordon Gould]

My TD7 hour meter was wired to run when the battery disconnect main switch was on like yours. Bothered me because I use it for maintenance scheduling and I often left the mains on by mistake too. I just took the instrument panel off and rewired the 12V side of the hour meter so it went to the run switch instead of the 12V battery line. Very easy and now the hour meter only goes when the run switch is on.

gg

 

[bswiv]

Thank you all for the ideas. Got sidetracked getting fire lines in place with the tractor so have not been back to the dozer yet.......but will run through the ideas on it.

 

[falfrenzy]

I was thinking low tech and just get one of those jet ski bungee cord safety disconnect things that goes around your wrist. And attach it to your switch, or on the panel near it. Conversely you could mount an eyelet to hang your keys on next to it while you are operating.

 

[MHarryE]

I thought the D5C powered the hour meter through an oil pressure switch so it would rack up hours only when oil pressure was above approximately 5psi. Obviously not the case on yours because of how it is working but that was Cat standard for your vintage machine.

 

[bswiv]

I thought the D5C powered the hour meter through an oil pressure switch so it would rack up hours only when oil pressure was above approximately 5psi. Obviously not the case on yours because of how it is working but that was Cat standard for your vintage machine.

If that is the case then I have some other problem?

This is a old Florida Forest Service unit so may have some oddities.........but I do not know how to check that. I know they sold it to me at 1487 hours with the pins having just been turned. That was in December of 2015 and I've not used it but maybe 100-150 hours.

 

[MHarryE]

It puzzles me because if the D5C is like our machines of that late 90s, early 00s era, the hour meter would be on a simple switch on, power goes to meter, ground wire to separate oil pressure switch on engine that closes to ground at 5 psi. In our (Paving Products) systems the pressure switch would need to fail closed. Our products in that range used a 3054, 3056 or 3116 engine. Those are either Perkins origin 305x engines or Cat Mossville 311x. Yours I believe is a 3046 Mitsubishi and this is where I get mixed up - may be designed in Japan. Still they should meet the Cat standard the company demanded so mechanics didn’t need to learn the variation of common systems on different machines. We mounted separate switches for the hour meter and hour meter. Frankly the Cat standard hour meter gave me fits due to reliability as a failure counted as the same hit as a blown engine. But they failed dead, not continuous run. The hour meter service box comes with a new meter and an adhesive label on which you write the hours to be added to the hour meter reading.

 

[bswiv]

It puzzles me because if the D5C is like our machines of that late 90s, early 00s era, the hour meter would be on a simple switch on, power goes to meter, ground wire to separate oil pressure switch on engine that closes to ground at 5 psi. In our (Paving Products) systems the pressure switch would need to fail closed. Our products in that range used a 3054, 3056 or 3116 engine. Those are either Perkins origin 305x engines or Cat Mossville 311x. Yours I believe is a 3046 Mitsubishi and this is where I get mixed up - may be designed in Japan. Still they should meet the Cat standard the company demanded so mechanics didn稚 need to learn the variation of common systems on different machines. We mounted separate switches for the hour meter and hour meter. Frankly the Cat standard hour meter gave me fits due to reliability as a failure counted as the same hit as a blown engine. But they failed dead, not continuous run. The hour meter service box comes with a new meter and an adhesive label on which you write the hours to be added to the hour meter reading.

You are right, it is a Mitsubishi engine.......actually the whole thing is. We're burning and working fire lines now and so long as I can get that done with the tractor the bulldozer will stay on the transport so it may be a while before I get to running down some of the ideas.

I have the shop manual for it, which has paid for itself ( $550!!! ) time and again......but can not find the hour meter in there.

 

[Gordon Gould]

On my TD7 a small oil pressure line ran from the engine up to the instrument panel where there was a Tee in amoungst all the wiring and gauges. One leg went to the analog pressure gauge the other to a pressure switch for the hour meter. The switch was failed open so the hour meter wouldn't run. To fix this one of the previous owners rewired the hour meter to a hot 12V line so the hour meter ran when the main switch was on. The pressure switch was in a hard place to get to and replace so rather than replace it I rewired the hour meter to the run switch which controls the fuel solenoid so hours accumulate when the run switch is on and stop when you shut down the engine. Not a perfect solution maybe but easy and way better than a battery line connection.

gg

 

[MHarryE]

The hour meter is called the service meter. I didn't see anywhere that you wrote the Serial Number prefix - there are 2 possibilities for the DC. The one I chose - my view of the electrical schematic is not clear. The item you are looking for is Switch - Engine Oil Pres (Ser Meter). On my schematic it is located on sheet 1 coordinates C6. It is normally open, closes at 21 */- 4 psi, opens at 13 +/- 4 psi. This is for serial numbers starting with 6PJ. The other option is 3MK. However I think you have a D5C Series III. The Service Hour Meter shown on the schematic is 6T-7337. Its not real easy to trace it down because my electrical schematic has 30 pages but from what I can see the Service Hour Meter is connected to wire 403 Green which then connects to the R terminal on the alternator. I am not sure if the R terminal is hot when the key is turned on. Its used for things like tachometers, voltmeters, etc.