7610 dual fuel tanks and fuel gauge

Our 7610 has dual fuel tanks and right now the
fuel gauge and temp gauge don't work quite
right (temp gauge) or at all (fuel gauge). I
am guessing the problem with the fuel gauge is
because it is an aftermarket dash that isn't
designed for dual tanks. My question is if I
buy another dash cluster for it, can I buy the
one made for a single tank and only hook up the
aux tank fuel level sender, since it will read
full until the top tank is empty and starts to
drop the level in the lower tank, which is all
I need to know to know if I am going to run
empty. New holland wants around $600 for a
whole new dash assembly with the dual tank fuel
gauge, or I could buy one for a single tank and
replace the gauge with a dual tank fuel gauge
for a little over half that. However, you can
buy the aftermarket clusters for about $100.

Also, is there anyone that makes wiring
harnesses for these tractors outside of NH?
They want about $1000 for the main harness.

Hurst

The main difference is that the tractors with dual tanks used a resistor that pressed onto the back of the gauge. #11A is what you need. Try that before you replace the whole cluster.

Also, these tractors were famous for lower sending units that never worked anyway because of rusty connections on top of the sending unit. Check that closely as well.

Bern, thanks for clarifying what the difference is! So I take it the two senders are supposed to be hooked to the gauge in parallel, not in series, so therefore, another resistor is needed in series with these two senders to bring the readings back to what they would be with a single sender?

I would just buy a fuel gauge, but unfortunately the entire cluster has been replaced on this tractor before with one that looks like:

http://www.ebay.com/itm/Ford-New-Holland-3610-4610-6610-7610-Tractor-Dash-Panel-Rev-Clock-Tacho-Gauge-/231485945829?pt=LH_DefaultDomain_3&hash=item35e5a337e5

I guess I could buy this style aftermarket:

http://www.ebay.com/itm/NEW-Gauge-Cluster-Ford-Holland-Tractor-540B-4610SU-7610S-4130NO-3230-3430-3930N-/171318160567?pt=LH_DefaultDomain_0&hash=item27e35bacb7

and buy the fuel gauge from NH.

Right now both senders read around 250-270 ohms, the top tank being a little over 3/4 of a tank and the bottom tank full. Does that seem about right? I would think they should be reading near 0 ohms when they are full so a full 10 volts (from the voltage stabilizer) is going to the gauge?

Hurst

Have you tried experimenting with the gauge at all? Checking to make sure you have 12v present with key on? "Flashing" the sender wire to ground to see if the gauge tries to move? If the gauge works, you might consider separate wires, one from each tank sender, and a switch somewhere to select which tank you monitor. Just a thought.

The gauge works when flashed to ground, but I don't get a reading with the senders. I need to experiment with some resistors and also check the resistance on the tanks as I use the fuel out of them. I have a funny feeling one or both senders might be dead.

Hurst

Not to suggest you disregard what was already said... but my first course of action would be to assure the cluster is adequately grounded.. It would seem to me that if both gauges are effected then you have a problem that is common to both; that being the ground. I've never dealt with the circuit for dual tanks on that particular tractor so I can't really comment on how it works... but the temp gauge is what makes me suspicious.

Rod

there is a cluster that needs the voltage stabilizer and one that did not.... my memory is foggy but did a 10 series not do away with the stabilizer? I would have to go pull the parts books, but at some point they went to the free floating gauges and it senders changed in resistance value... sorry if this is not correct. but iirc,,,the fuel changed from 170 ohms to 270 ohms or something like that. Temp sending unit changed also. its was in one of the change-over addendums.


At least I can hide my own easter eggs.

Yeah, I was looking in the parts book last
night, and I think something like 83 or so was
the change over. I have an 86 tractor, but the
aftermarket dash is the one with the voltage
stabilizer and I have a 270 ohm sender in the
tank, which I think is bad because it was
reading 270 ohms to ground with 3/4 of a tank
in the top and a full tank in the bottom. That
would also probably explain the temperature
gauge not being as sensitive as our other
tractor with the original cluster, but at least
I have some reference of temperature now...

Hurst

Hey Rod! I want to thank you (and Bern) for the help with the PTO brake band on this tractor! Sure enough, it had broken at one of the little loops where the pin goes through for the engagement lever. Put in a new NH band and adjusted it and put it in. I have to say, if I did it again, I think I would drain the 25 gallons of fuel and remove the lower tank and do the rear split. There were some times going through the top cover with L/M on the tractor that had me saying some choice words to the old tractor lol!

I think it sounds like I have an old-style cluster with the voltage regulator on a tractor with newer style senders. The tractor is an 86 model, but the replacement cluster that a repair shop put in probably 10 years ago is the white/black striped back one with the voltage regulator on the back instead of the black one with the yellow lines for the tach. Also, would the sending units be bad if they both read 270 ohms with full tanks? Shouldn't a full tank be closer to 0 ohms to ground?

Hurst

10 series tractors never used a voltage stabilizer. If your dash has one, it's not right! If it has a voltage stabilizer, then it also likely has bi-metal gauges, which is also NOT right! That's one reason why your senders appear to not work. The senders are different between magnetic gauges and bi-metal gauges. BTW, bi-metal gauges slowly return to full left when the key is turned off, whereas magnetic gauges tend to randomly float with the key off.

I don't recall off the top of my head what the resistance readings of the sensors should be. Suffice it to say that the upper and lower should read similarly to each other.

As for the brake band replacement without splitting the tractor, I could have told you that you would be wishing you didn't! I looked into that once and said "No way!" I didn't even think it was possible. I doubt you adjusted it.

Adjusting it was the fun part. I probably could have done it through the hydraulic pump hole with another person on top, but instead, I just measured the distance of the lever to the band in the relaxed position, then pulled the pin out (using a screw driver with an extendable magnet to hold it in place), rotated the band up to where the lever/clevis was on top of the drum, shimmed the lever to the distance I measured when it was hooked up, and adjusted it while it was on top, then slide it all back down. I did have to take the locating pins out and slide the valve body back to do this. I just marked the adjusting bolt/pin and returned it back to that position, which was right where it started picking up torque just slightly. It is possible, but I would probably just split it last time. Someone said it was kind of a draw if you had the lower fuel tank, but after doing it once with L/M on the tractor, I think I would recommend the other way lol. When it was all put back together, it seems to be working like a charm. The old mechanic told me to adjust a new band, he'd always leave them with just a little drag so they wouldn't be too loose once they wore into the drum. I left mine where I could just barely turn the 540 shaft by hand from the drag, and the lever only moved about 1/3 of it's travel to engage the brake. I hope it was close enough to last the rest of the life of this clutch pack!

As far as the gauges, it definitely sounds like I have a mix-up of gauges and senders. Isn't the resistance of the sender to ground supposed to be less the fuller the tank? So if I am reading 270 on a full tank and 3/4 tank, then my sender is just sending an empty signal? Or is full resistance a full tank with the magnetic gauges? The gauges definitely are bi-metallic that return slowly when the key is turned off. Kind of like my old Smith gauges in my MGB.

Hurst

If you have bi-metallic gauges, then definitely they are the wrong gauges, and will NOT work with the original sending units. Having said that, I do not know what the resistance values for those senders are off the top of my head, which is why I suggested comparing the two (upper and lower), which should be similar.

You need to find a dash cluster with magnetic gauges, remove any voltage stabilizer that someone may have stuck on it, and get that dual tank resistor that I mentioned earlier.