ford 3930 fuel guage question

Granpa49 · Feb 20, 2016

Can you swap out the fuel guage on a Ford 3930 without having to change out the entire instrument cluster? I'm finding plenty of clusters for sale on one but no single fuel guages. I checked the sending unit and at the current fuel level (about half a tank) I read 225 ohms resistance across the terminals on the unit. I checked the wire at the guage and got the same reading. The red wire at the guage is hot and the ground wire checks ok. I am assuming the guage itself is bad. Not having a manual I've no idea what the resistance should be but 225 ohms seems rational. Any experience with this or technical info would be appreciated.

ovrszd · Feb 20, 2016

Hope you get an answer. My gauge don't work on my 3910. Reads full all the time.

Granpa49 · Feb 25, 2016

Nice 4WD.

ovrszd · Feb 25, 2016

Granpa49 said:
Nice 4WD.

Thank you. Thought it deserved some air time.

ovrszd · Feb 25, 2016

Can't believe we haven't gotten some advice on this problem with 136 "visits"......

Winmac · Feb 25, 2016

Touch the sending unit wire to ground, needle should move to full otherwise gauge is bad.
There are basically two standards for resistance of fuel sending units, are there any part numbers stamped on the ring?

FredH · Feb 27, 2016

know nothing about your particular tractor , But in looking at parts for it on Messicks , Your in a better situation than Me on My TC 30 !!

When my guage went out . it was right at $100 for new guage . Now they are $180+ .

Yours shows the following :

Assy., Fuel, L/Auxiliary Fuel Tank, Start Year: 01-MAR-90 E5NN9207AA $114.46

Assy., Fuel, W/Auxiliary Fuel Tank, Start Year: 01-MAR-90 E5NN9207BA $123.58

In drawing , First one listed is on the right side of panel .

In looking at drawing , it just appears that you would have to disassemble cluster , I assume , to the degree that You could remove , replace gauge .

Since gauge is listed seperate , Then I assume that " Yes " it is replaceable .

Messicks | Your home for New Holland, Case IH, Kubota & More... ( left side of picture , were it states online parts , scroll mouse over that and a drop down menu appears . Slide cursor

over New Holland on the right side of that menu and click . On left side of next page , click in the search box and type 3930 and search . Brings up a list on

the left of the componet sections . scroll down to instrument cluster and click . )

Fred H.

ovrszd · Feb 27, 2016

Nice work Fred.

I'm suspecting my problem is the tank unit. Reason I think that is because my gauge goes to full when key is turned on regardless of fuel level in tank?

FredH · Feb 27, 2016

My issue on my TC 30 was initially the gauge itself . But When I bought a universal gauge and sender unit to replace original , the sender eventually went out and had to replace it . On the senders that have a lever type motion , there are Brass contacts that the contacts slide on as the fuel level goes up and down . What usually happens is those Brass contacts break , wear out , etc... , and electrical contact is broken in that area .

Although a Pain to disassemble , Before purchasing either a gauge or sending unit , Pull sending unit , re-connect wires and manually move sender float up and down . That is how I found the issue with my first replacement sender unit . It had " Dead Spots " .

Fred H.

ovrszd · Feb 27, 2016

FredH said:
My issue on my TC 30 was initially the gauge itself . But When I bought a universal gauge and sender unit to replace original , the sender eventually went out and had to replace it . On the senders that have a lever type motion , there are Brass contacts that the contacts slide on as the fuel level goes up and down . What usually happens is those Brass contacts break , wear out , etc... , and electrical contact is broken in that area .

Although a Pain to disassemble , Before purchasing either a gauge or sending unit , Pull sending unit , re-connect wires and manually move sender float up and down . That is how I found the issue with my first replacement sender unit . It had " Dead Spots " .

Fred H.

Thanks for the info Fred!!! I'll try that. Just at a glance I think I've gotta remove the sheet metal over the tank before I can get the sender out. That'll be a trick.....