Ford 8000 Fuel gauge and sending unit. Also tach

Wanting to find out if anyone knows how to test to see if the sending unit in the tank is actually "working". Also, anyway to test if the fuel gauge in the dash is working? I do know the fuel gauge and the temp gauge on the dash do not work, but the back light on the cluster for the fuel and temp does work.


Another question. The tach does not seem to work properly. The needle is broke and if you are running the tractor at a certain position with the throttle, the round circle in the middle of the tach in which the needle should be on will start rotating all the way around. Any clues on how to fix any of these items and or test them? Especially the fuel issue. Like to know how much fuel is left and would be nice to know the temp as well. Tach I can deal with if need be.

Thanks,
Justin

I have yet to figure out how to "test" these items even with the shop manual. Anyone have a clue? Also anyone know anybody that has a used tach or proofmeter for this tractor to sell?

Again any help would be appreciated!

The sending unit can be tested with a ohm meter. Remove the sender from the tank and attach a ohm meter(red lead) to the lead from the sender and the black lead to the sender body. Move the sender arm up and down slowly and watch the ohm meter to see the resistance rise and fall at a smooth rate.
The gauge can be checked by getting access to the rear of the gauge. Turn on ignition and remove ground wire from gauge. The needle should drop to the left of empty. Connect a wire to a good ground and touch it to the sender side of the gauge. The needle should go passed the full mark.

Someone was parting one out on ebay, cant remember who.

FWIW,
For the sending unit, you could also use the wire to it now and take an ohm reading.
Then use a coat hanger thru the fill hole to hook the float. lift up and the ohm reading should change. Push down and the same.
This way you don't have to remove the sending unit if it's good and you are checking that the sender is grounded properly and the wire.
HTH
BTW: I used this method to work on a new fuel gauge in my 1964 Ford 4000. I used a sending unit for a Ford 7000 I had extra and a SW Gauge that I purchased. By bending the float rod, I was able to get empty correct and full to read close to full. Was a good retrofit for the 12 volt conversion.
Keith

ok, I will try the grounding method on the actual gauge to see if the gauge is even working. The sending unit I like the idea of using the coat hanger better then taking the unit out because the way my luck is I would end up having a bad leak around the sender unit and have to fight with it to get a good seal. I will try checking ebay again but did not see anything for a tach or for the proofmeter (fuel gauge and such)


Anyone know if any other model/years of proof meters and tachs work with this ford 8000?

Thanks again for the help!

If this 8000 is similar in instruments to those Fords preceding it, then the one common item to the fuel & temperature gauges is the instrument cluster voltage regulator. When both stop working, that is the first ting I would look at.

(quoted from post at 10:36:42 06/16/17) If this 8000 is similar in instruments to those Fords preceding it, then the one common item to the fuel & temperature gauges is the instrument cluster voltage regulator. When both stop working, that is the first ting I would look at.

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Do you happen to know the exact location of that item and how to do a "test" to see if that is the problem?

I do not know the "exact" location on the 8000, but others that I know of are on the back side of instrument cluster. Usually thin rectangular package with two wires and a ground. When operating properly, it receives 12v and has an output similar to a turn signal blinker, on/off/on/off/etc, thus producing an 'average' voltage of about 5 volts. It will be supplying only the temperature & fuel gauges. When working, sometimes, you can see a very tiny wiggle of gauge needle as it turns on/off/on.

(quoted from post at 15:24:04 06/16/17) I do not know the "exact" location on the 8000, but others that I know of are on the back side of instrument cluster. Usually thin rectangular package with two wires and a ground. When operating properly, it receives 12v and has an output similar to a turn signal blinker, on/off/on/off/etc, thus producing an 'average' voltage of about 5 volts. It will be supplying only the temperature & fuel gauges. When working, sometimes, you can see a very tiny wiggle of gauge needle as it turns on/off/on.

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Ok, I ended up taking some photos and replacing a couple of the small bulbs that are for the tach and proof meter. I took a test light, grounded it out and check for hot wires with ignition on.

Note: the tester I use is 6 volt to 24 volt.

Here are the photos that show what the gauges look like with the key on (before replacing bulbs and after).

I have tried to take best photos I could at the time and then of course pinpoint out the wires that were "hot" with key on. Maybe this will help people. I might also have to try the coat hanger trick If I know how to do it to see if fuel gauge moves. What was the other way of testing the sending unit and or the actual gauge.

Well I have not heard anymore updates on if anyone has a clue on how to figure this out. Also, do you know where the engine coolant temp sensor is located on this engine? is it the one located on the left side if sitting on tractor over by the oil filter?

Also, for some reason when we filled the tractor up with diesel, the fuel gauge went all the way up, but then quite working again. But, this to me means it could just be a bad ground or something because of bouncing around. Either way would like to at least get the temp gauge fixed to know operating temp and also be nice to know the fuel as well so I do not run it out.

Again, thanks for the help. I have looked at the wiring diagram and can't figure this out stuff out. If I ground out the wire going to the sending unit in the fuel tank, would the gauge itself on the dash move? Same way with coolant sensor?

Any help is appreciated with this. Thanks

Also, apparently my last photo of the "power" wires did not upload, so i am uploading them again. Hopefully it shows.

I can only rely on other exoeriences, your photos/information/measurements and wiring diagrams, as I have never worked on an 8000 & easily defer to those who have! Given that, it looks to me like the black wire that you labeled 'hot' at lower left of photo simple plugs onto a mounting bracket screw (does it?). Black is virtually always used for grounds on Ford tractors & in my wiring diagrams. I suspect that is is in fact ground & that it is not making a good connection or is broken somewhere along its length. The gauge cluster must have a ground in order to function. Verify that wire.

(quoted from post at 08:53:30 06/21/17) I can only rely on other exoeriences, your photos/information/measurements and wiring diagrams, as I have never worked on an 8000 & easily defer to those who have! Given that, it looks to me like the black wire that you labeled 'hot' at lower left of photo simple plugs onto a mounting bracket screw (does it?). Black is virtually always used for grounds on Ford tractors & in my wiring diagrams. I suspect that is is in fact ground & that it is not making a good connection or is broken somewhere along its length. The gauge cluster must have a ground in order to function. Verify that wire.

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I agree that black to me has always been ground, but for some reason that is not the case with this wiring. Not sure if sometime in it's life if someone messed with the wiring or what, but all wires appear to be original from what I can tell. Which, if the black is suppose to be ground means they have somehow switched the polarity. I do know the battery is not positive ground. It has the regular negative ground.

Now, what I done to test my theory was to take a ground wire like someone had stated, run the ground wire from the actual battery and removed the "red ground wire" off the fuel gauge. I then put the ground wire onto the post that the red wire come off of. Once I done this, the fuel gauge went all the way past the fuel mark, which would tell me that the gauge itself "should" be ok.

Now, I done the same thing with the temp sensor on the dash and it also moved all the way, so that "should" also verify it works, but here is the kicker.

I then hooked all that back up, I then tried it and got nothing. Filled tank up with diesel, still nothing. So, i took a ground wire and touched the fuel tank sensor that goes into the fuel tank. Once I do that, the gauge starts moving and will go all the way to past fuel if I keep that ground wire touching. Same with the temp sender unit as well. But if they are both plugged into their sensors (the one plugged into front of motor for temp and one mounted on tank for fuel gauge), then they do not work. Makes no sense to me. Maybe someone else with some better insight or something could understand this as it really does not make sense to me.

I agree, black has always been negative for me, but not on this tractor. :?:

(quoted from post at 17:39:54 06/15/17)
The gauge can be checked by getting access to the rear of the gauge. Turn on ignition and remove ground wire from gauge. The needle should drop to the left of empty. Connect a wire to a good ground and touch it to the sender side of the gauge. The needle should go passed the full mark.

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Tried this on both the temp gauge and fuel gauge and they both work. But once plugged in they do not work.......

It was suggested a day or two ago that you measure the resistance of each sender, Ohmmeter with one lead on sender terminal and other touching sender body (ground). Has that been done? What were readings?

Also, that black wire on gauge cluster.....please unplug it and measure voltage on wire/plug as well as voltage on the lug it was plugged onto.

(quoted from post at 11:30:34 06/23/17) It was suggested a day or two ago that you measure the resistance of each sender, Ohmmeter with one lead on sender terminal and other touching sender body (ground). Has that been done? What were readings?

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I have not got to that part yet which I plan to do. I know it is a dumb question but with everything going on lately, i can't remember what I need to have my multi meter set on. Do you know what "settings" it should be on when I measure these? Wanna make sure I got the right settings so I can get an accurate reading. Thanks again!

Attaching picture right now.

(quoted from post at 11:58:08 06/23/17)

(quoted from post at 11:30:34 06/23/17) It was suggested a day or two ago that you measure the resistance of each sender, Ohmmeter with one lead on sender terminal and other touching sender body (ground). Has that been done? What were readings?

Click to expand...

I have not got to that part yet which I plan to do. I know it is a dumb question but with everything going on lately, i can't remember what I need to have my multi meter set on. Do you know what "settings" it should be on when I measure these? Wanna make sure I got the right settings so I can get an accurate reading. Thanks again!

Attaching picture right now.

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So, apparently uploading photos on this forum is not working for me, so instead I am just using my own website and linking the photo their for you all to see the photos. Makes it easier for me

(quoted from post at 14:58:08 06/23/17)

(quoted from post at 11:30:34 06/23/17) It was suggested a day or two ago that you measure the resistance of each sender, Ohmmeter with one lead on sender terminal and other touching sender body (ground). Has that been done? What were readings?

Click to expand...

I have not got to that part yet which I plan to do. I know it is a dumb question but with everything going on lately, i can't remember what I need to have my multi meter set on. Do you know what "settings" it should be on when I measure these? Wanna make sure I got the right settings so I can get an accurate reading. Thanks again!

Attaching picture right now.

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on't see any picture, but I expect readings of somewhere between Zero and perhaps 200 Ohms. Less than 1K for sure.

(quoted from post at 12:06:37 06/23/17)

(quoted from post at 14:58:08 06/23/17)

(quoted from post at 11:30:34 06/23/17) It was suggested a day or two ago that you measure the resistance of each sender, Ohmmeter with one lead on sender terminal and other touching sender body (ground). Has that been done? What were readings?

Click to expand...

I have not got to that part yet which I plan to do. I know it is a dumb question but with everything going on lately, i can't remember what I need to have my multi meter set on. Do you know what "settings" it should be on when I measure these? Wanna make sure I got the right settings so I can get an accurate reading. Thanks again!

Attaching picture right now.

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on't see any picture, but I expect readings of somewhere between Zero and perhaps 200 Ohms. Less than 1K for sure.

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I had to attach it via using my own website server. It should show my meter (mine is different color and such, but same company).

start with 200 (just above yellow on/off sw.) if off scale, try 2000

(quoted from post at 12:27:40 06/23/17) start with 200 (just above yellow on/off sw.) if off scale, try 2000

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ok, Thanks I appreciate it! I will attempt to do it today but it is raining out and I have some other equipment to work on. I will give you results once I find anything out (if anything)

(quoted from post at 15:31:39 06/23/17)

(quoted from post at 12:27:40 06/23/17) start with 200 (just above yellow on/off sw.) if off scale, try 2000

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ok, Thanks I appreciate it! I will attempt to do it today but it is raining out and I have some other equipment to work on. I will give you results once I find anything out (if anything)

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ny thing further on instruments?

(quoted from post at 10:13:58 06/30/17)

(quoted from post at 15:31:39 06/23/17)

(quoted from post at 12:27:40 06/23/17) start with 200 (just above yellow on/off sw.) if off scale, try 2000

Click to expand...

ok, Thanks I appreciate it! I will attempt to do it today but it is raining out and I have some other equipment to work on. I will give you results once I find anything out (if anything)

Click to expand...

ny thing further on instruments?

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I actually had to put the instruments back together for now because I have to use the tractor. The next chance I get a break from using it, plan to do some more testing

(quoted from post at 10:03:58 07/01/17)

(quoted from post at 10:13:58 06/30/17)

(quoted from post at 15:31:39 06/23/17)

(quoted from post at 12:27:40 06/23/17) start with 200 (just above yellow on/off sw.) if off scale, try 2000

Click to expand...

ok, Thanks I appreciate it! I will attempt to do it today but it is raining out and I have some other equipment to work on. I will give you results once I find anything out (if anything)

Click to expand...

ny thing further on instruments?

Click to expand...

I actually had to put the instruments back together for now because I have to use the tractor. The next chance I get a break from using it, plan to do some more testing

Click to expand...

ood deal. Yours is an interesting problem. Simple ones are not very interesting. My focus is still on the cluster ground.