LINES GP-AIR 2566171 - Caterpillar

3T0376 (24V) and the 9X0253 (12V) Magnetic Switches used as power relays on machines may be intermittent. White corrosion on the nuts of the power studs for the relay contacts may cause an open circuit condition. Instead of replacing the relay, the corrosion can be cleaned from the nuts by lightly wire brushing the nuts to remove the corrosion. Apply a thin coat of Dielectric 8T9020 Grease to the connection at assembly. Effective with date code 40M (40=40th week M=1992) the plating has been improved to help prevent the white corrosion of the nuts.
Be sure to open or turn off the battery disconnect switch before servicing the 3T0376 or 9X0253 Magnetic Switches. On 12 Volts Machines without a battery disconnect cable switch, open the battery disconnect cable between the negative terminal of the battery and frame ground of the machine.