No tachee, no dirty!

[EyeDigU]

1997 New Holland LX665 skid steer. Replaced both starting relays for one problem (corrected), but have no tach reading, only 000's. Prior to repair the tach indicated 000 the last time. I have the overhead console for RPM, hours, temps, etc. Pulled the alternator and had it tested and it is okay between 45/50 amps. All wiriing appears to be on, but am I missing something? One note, when I put the key in, the board reads 5.2 volts, and has for some time, but the battery will crank and never tire and all other functions are fine. Alternator starts out around 11.5/12.0 amps, but quickly moves through 13 and up to 13.5/14.2. Any ideas on what to check?
Thank you,
EyeDigU

 

[jinman]

Alternator starts out around 11.5/12.0 amps, but quickly moves through 13 and up to 13.5/14.2. Any ideas on what to check?

Do you mean volts instead of amps? Your alternator's voltage output depends on the load and would increase to the normal 14.2 vdc fully charged indication if your battery is being recharged from the start. However, if your current is constantly increasing, that would not be normal as current is normally highest just after starting and goes down when the battery recharges. I'm thinking you surely meant volts instead of amps.

. . . but have no tach reading, only 000's. Prior to repair the tach indicated 000 the last time. I have the overhead console for RPM, hours, temps, etc. Pulled the alternator and had it tested and it is okay between 45/50 amps. Any ideas on what to check?

"Prior to repair. . . " does that mean that the tach failed before in a similar way and was repaired? I'm a bit confused on this.

Your tachometer works off a pulse stream from your alternator. There should be a separate plug on the back of the alternator that goes to the tach. I'd make sure that wire is plugged in properly and you have good continuity in the wire all the way to your instrument panel. Your tach might be stuck or it could be bad and need replaced, but I'd check that the wire is not broken, loose, or has bad contact in a connector somewhere. If the tach is repeatedly failing that seems to indicate something else is bad and causing the tach to fail. Have you ever noticed condensation form inside your instrument panel?

 

[EyeDigU]

Sorry, as I meant volts. With the key in the dash, it indicates 5.2, and upon starting, it reads 11.5/12.0 and then ramps up to 13.5/14.2 without a problem. The starter relays were replaced as one was bad (not working). Prior to replacing them the tach (digital read out in the overhead dash console) stopped reading. It had been working perfectly since new. I pulled the alternator and had it tested, but prior to pulling it, possibly I may have broken or dislodged the tach wire. Question is, which one and where is it. I don't see anything obvious though. The nut affixed wires (2) are clearly secure, although I have yet to test them for continuity. There is one plug in wire that terminates in a rubber end and only plugs into a hole on the alternator. The hole has no hard connection, but rather appears to be an inductive type coupling (tach?). Where do I start to look and for what? I'm not stupid, my electrical experience/savvy is limited, but I can follow directions. So, I'm ready to listen. Do you have any ideas? Thank you.

EyeDigU

 

[jinman]

There is one plug in wire that terminates in a rubber end and only plugs into a hole on the alternator. The hole has no hard connection, but rather appears to be an inductive type coupling (tach?).

Does your alternator look like the one in the attachment? Are you saying that there is not a connector attached to the back of the alternator where I labeled it "tach" and having two wires going up to the instrument panel. The only thing I can imagine that might be around those wires is a filter coil to remove static interference, but your description seems to be something very different.

BTW: According to the info I have found, your LX665 uses the same alternator as my NH TC45D and many other compact tractors. However, the mechanization of your tachometer might be from some other source. I'm doing a bit of assumption because my tach is driven directly off the connector shown below on the back of the alternator.

BOGUS INFO ALERT!

Dang it! I looked at the wrong connector. The tach connector is a single wire directly below and sligtly to the left of the labelled connector. On my tractor it has a pink wire going to it. The incorrectly labelled connector is for your alternator charge light on the dash and the voltage regulator sensing lead. Sorry about the misinformation.

 

[jinman]

I was going to pull my tach wire out of my alternator and look at it, but it is buried behind the exhaust shield and I couldn't get to it without completely removing the alternator. I'm not sure what the connector looks like, but my schematic shows it is attached to the P terminal (the single terminal in the last photo) and the Repair Manual says that this terminal has a pulse output that is 1/10 of the alternator's rpm and is used for speed detection and the tachometer.

 

[EyeDigU]

Does your alternator look like the one in the attachment? Are you saying that there is not a connector attached to the back of the alternator where I labeled it "tach" and having two wires going up to the instrument panel. The only thing I can imagine that might be around those wires is a filter coil to remove static interference, but your description seems to be something very different.

BTW: According to the info I have found, your LX665 uses the same alternator as my NH TC45D and many other compact tractors. However, the mechanization of your tachometer might be from some other source. I'm doing a bit of assumption because my tach is driven directly off the connector shown below on the back of the alternator.

BOGUS INFO ALERT!

Dang it! I looked at the wrong connector. The tach connector is a single wire directly below and sligtly to the left of the labelled connector. On my tractor it has a pink wire going to it. The incorrectly labelled connector is for your alternator charge light on the dash and the voltage regulator sensing lead. Sorry about the misinformation.

I viewed a picture of your alternator (or was it a stock image?) and have included 2 photos of the back of mine. While similar, it appears as though the terminals are mirror images of one another, or pretty close to it. The YELLOW/GREEN wire combo on mine is what you labeled as TACH and the PURPLE wire on mine plugs into hole adjacent to the YEL/GRN plug. It does not have a spade connector, but rather just a snug fit into a rectangular 3-dimensional hole. the PURPLE wire seats but it is rather taut (perhaps too taut) and maybe broken or similar. Hope this helps you because you're definitely helping me. Thank you!

EyeDigU
William

 

[EyeDigU]

Jim,
I'm always 10 minutes behind you. Using your original picture (I only received one) which wire is the tach?

Thanks again,
William

 

[jinman]

William, thanks for the photo. I looked up the part number for your LX665 on the internet (messicks.com) and they showed the same alternator configuration and part number as mine. That alternator you are showing is similar, but definitely different. The illustrated parts breakdown online also is exactly the same as mine.

I do suspect the purple wire is the tach output and maybe it just picks up the rpm by induction as you said. I think you are on the right track. If it's tight, the additional stress from a vibrating engine would only make it worse.

BTW: My tach sticks quite a bit and a sharp rap (a hard tap really) on the face of the instrument panel makes it spring to life and work fine for several days before it might stick again. I'd love to have an electrical schematic for your tractor, but they are just not available unless you have an owner's manual.

 

[jinman]

Here is a photo of the alternator labelled correctly. This photo is from a vendor's site and is not mine. I just copied it here, but my alternator looks like this one.

EDIT: It might be a mirror image of the real alternator. They easily could have this image reversed, but there is a lot of separation between the two connectors on my alternator and not close like yours.

 

[EyeDigU]

Jim,
Thanks for the quick reply. I will check the purple wire for breakage and so forth. BTW, is your tach a mechanical unit or a digital readout in an instrument panel as I have? Just wondering. I'll pull the panel to make sure all is clean, connected, and not rusting. I'll go to the site that you gave me and plunk around to see what I can. The worst of it is that I got an Owners Manual (big two-tone blue book) with my machine when I bought it new, but can't locate the manual. I'm going to start looking in 5 minutes, but it could be just about anywhere. Thank you very much for your help and if you think of anything, by all means drop a line. I really appreciate it.

William