Jd 310d bachoe no f or r

[Ham162]

My neighbors 310d backhoe has been given him fits . He has been having to cycle the brake switch to get it to go in F and R so I decided to check it out for him. What I have found is a chattering brake relay and switched it out with other relays alike the chattering continues in the same location . It clatters only when you turn the brake switch to on , and will quit chattering when you rev up the engine. At that time it still won't go in F or R all the time just sometimes. The voltage to the coil on the brake relay fluctuates from 11.9 to 13.9 volts . Voltage at the batteries with engine run ing is 13.9v . Today I went under to check the brake and had him turn the brake switch on and off and the rod only goes in after he revs the engine up. Is it the alternator not giving enough volts or something else like the switch ? I have no schematics or wiring diagrams can't see the valves or actuator that operates the brake. Any advice on what to check or do next would be very appreciated. Thanks

[don45640]

Run a new jumper wire to it and see if the extra current actuates better.Might be a weak wire connection or corroded. don-ohio (:^)

[ThomasH]

If the voltage fluctuates like that, it's either the wiring that feeds the relay or a connection in that wiring, or the voltage regulator for the alternator. To test out the alternator turn on the headlights, and see if they flicker. If not, it's probably not the alternator.