# JD 2555 Schematic, or wire color between tachometer sensor on alternator



## pvanderlugt (Feb 19, 2021)

I have a 2555 on which the fuel gauge and tachometer do not currently work. I have checked the sensor at the alternator, and it is putting out the correct "variable" volts to send to the tachometer. And I have a new tachometer to install. I'm looking for the correct wire on the tractor, to plug into the sensor on the back of the alternator, but I don't know what color I'm looking for. Does anyone have the schematics for this tractor, that includes wire colors, and or, the position on the plug at the Tachometer, that should be run to the sensor on the alternator?

I hope that is an understandable question.

Thanks for any and all help,

Pete
Lafayette LA


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## Tx Jim (Jul 28, 2020)

Its my understanding that magnetic pickup for speed/hour meter aka tachometer is located on LH front of engine not at alternator


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## pvanderlugt (Feb 19, 2021)

Tx Jim said:


> Its my understanding that magnetic pickup for speed/hour meter aka tachometer is located on LH front of engine not at alternator


Hey Jim,

I have a technical manual on the tractor, that describes a outlet on the alternator, that put's out between .5, and 7 V, based on the RPM. As I read this manual, that is the feed to the tachometer. But for some reason, the previous owner to this tractor, clipped the wires to certain circuits, and the tachometer is one of them. So I don't know the color of the wire to look for, and re connect. 

I'll look where you've pointed, and see if I also don't see a sensor in that location, that may feed a signal based on RPM.

Do you know the wire color that feeds the Tach?

Thanks,

Pete


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## Tx Jim (Jul 28, 2020)

I guess your tech manual doesn't have the tach wire info? .


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## pvanderlugt (Feb 19, 2021)

Not that I have unearthed yet. I'm also not a trained mechanic. So sometimes it takes a while for me to decipher the information in them. There are two plugs with about eight wires per, coming from behind the tach. For all the lights, etc. and one is the tach, I just haven't thought of a way to identify which one is the tach. 

I'll keep reading the manual over. It has some electrical schematics, but the color of the wire is not described on any of the schematics I've found.

Thanks again, you've helped me multiple times already.

Pete


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## Tx Jim (Jul 28, 2020)

My 2040 Tech manual has wiring identified with #s & colors located under title ''wiring diagram" on page before wiring schematic. Do you have JD tech manual or some aftermarket variety?


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## pvanderlugt (Feb 19, 2021)

Hey Jim,

I've saved your info, so I can text when I am in front of the tractor. I went back to the manual after you wrote, and finally saw a layout of each pin, running to the two connectors. When I'm at the tractor, this should yield me the color of the wire. I'm also going to look for the sensor in the location you mentioned.

I appreciate your help once again.

I wonder why the previous owner would have clipped the RPM, and fuel gauge circuits? Has me scratching my head a bit. Otherwise, the tractor seems in such good shape.

Pete


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## pvanderlugt (Feb 19, 2021)

pvanderlugt said:


> Hey Jim,
> 
> I've saved your info, so I can text when I am in front of the tractor. I went back to the manual after you wrote, and finally saw a layout of each pin, running to the two connectors. When I'm at the tractor, this should yield me the color of the wire. I'm also going to look for the sensor in the location you mentioned.
> 
> ...


Hey Jim, (or anyone else who would like to chime in.

I read somewhere, I think in one of these discussions, that I'm supposed to idle my tractor, when checking the hydraulic fluid with the stick back by the PTO. Is that correct? I don't see mention of that in the operators manual. 

Also, I see mention in the owners manual, of using brake fluid for the clutch? And there is supposed to be a resevoir somewhere? Do you know where that is? I always thought that was part of the Hydraulic system. I have the turbo motor, which I believe is the TSS transmission.

I just got my tractor pulled into the open today, and hope to be back on the tachometer this week.

Thanks,

Pete


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## Tx Jim (Jul 28, 2020)

Older JD utility tractors were supposed to have engine idling when checking hyd oil level BUT I'm not sure if 55 series is included. 

Hyd controlled clutch is only utilized on 50 & 55 series utility tractors with a cab. Clutch operation reservoir is accessed by removing cowling in frrt of dash. Dot 3 brake fluid is correct.


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## pvanderlugt (Feb 19, 2021)

Tx Jim said:


> Older JD utility tractors were supposed to have engine idling when checking hyd oil level BUT I'm not sure if 55 series is included.
> 
> Hyd controlled clutch is only utilized on 50 & 55 series utility tractors with a cab. Clutch operation reservoir is accessed by removing cowling in frrt of dash. Dot 3 brake fluid is correct.


That seems to make sense, on both accounts. The operators manual I have for my tractor, has info on the hydraulic level, in two sections, neither mentions idling the tractor, and in fact, mentions that you make an effort to check the level when the oil is cold. So I'm going to take that as an indication that I should check the level when the tractor is off.

I finally found a picture of the clutch resevoir they are referring to, and mine definitely does not have that plastic resevoir.

Once again, I very much appreciate your help. 

I wonder, is there a way for us to trade emails? Mine is [email protected]. I hope it's not against the rules to include that.

Pete


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## Tx Jim (Jul 28, 2020)

I attempted to send you an email but it failed. Check your PM on this forum


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