JOHN DEERE FUEL GAUGE:
JD COMBINES FITS: : 3300, 4400, 4420, 6600, 6602, 7700 
JOHN DEERE - 2520, 3020 (SN: 123000 & up), 4000, 4020 (SN: 201000 & up), 4320, 4520, 4620, 500A (Sn: 123114 To 152141), 500B, 5020 (SN: 25000 & up), 6030, 7020, 7520;
REPLACES: AR45436, AT375294 
12-Volt Negative ground
Housing Depth : 1.378" / 35MM
Resistance 30 - 250 Ω (ohms)
Gauge must be grounded to work properly...Gauge now has an extra grounding terminal, to run a ground wire to the sending unit.