got a 2003 polaris sportsman 500 ho the left front wheel dont seem to lock in 4x4 right side does any help or advice would be great thanks

 

I'd take it in steps. Drain and refill the hub fluid and see if it helps. Check that the small wiring connectors under the front panel(gray and brown wires) have a good connection. You can also pull these connector apart. Use a test light or ohm meter and while in gear,awd switched on along with the key on, test that you have power to each gray wire. If you do,but still don't have awd to one wheel you could have mechanical problems in the hub system. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse
Plus here's one fix if you have a bad ground problem.

 

thanks for the help i checked the wires have power on both sides right and left so going to change the oil and try that what oil should i uses i run amsoil in it for motor thanks again

 

I'd use either Polaris Demand Drive hub fluid(if any is still around) or the latest Demand Drive Plus hub fluid for the awd systems.The Plus came out to eliminate two different oils on atvs that had adc control that used a "special" fluid of its own along with the hub fluid. The Plus just simplified it to where you could just use one oil in all systems.. Some people still use atf in the older hub models,but I'd stick with the thinner Polaris hub oils.