I can put my truck in 4-wheel drive and the RFW SWITCH lights up, showing my hubs are locked. But the front tires do no pull. I checked all my connections, and wires, all look good, the vaccum hoses are plugged up correctly. What else could i look for in the 4-wheel drive system that could be going bad or not working. The truck is a 1989 Mazda B2600i 4X4 (Manual Tranmission). I have done put so much money in the truck, now i need to get the 4 wheel drive working. Here is a parts list of everything i have installed on the truck.

New Tires ($200)
Alignment ($42)
Water Pump ($75)
Put Ball Joints On ($195)
New Gas Tank ( $131)
New Fuel Filter ($15)
New Plugs, Wires & Distributor Cap ($40)
New Battery & Terminals ($60)
Had New Windshield Put In ($195)
Put New Back Brake Shoes On ($17)
Put New Wheel Cylinders On Both Sides ($38)
New Disc Brake Pads ($12)
Put New Electric Cooling Fan On ($74)
Put New Upper Arm Shaft Kits On ($280) (Both Sides)
Put New Radiator On ($133)
Put New Distributor On & Timed It ($285)
Put Oil Pan Gasket On ($12)
New Intake Gaskets ($15)
Water Outlet Gasket ($4)
Thermostat Housing Gasket ($6)
New Clutch Kit ($234)
New Flywheel ($112)
Slave Cylinder Rebuilt Kit ($7)
Put New Clutch Master Cylinder On ($40).... as you can see, i think i need the spend some more money.. lol any help would be great!

 

what it sounds like to me is a solinoid or somthing there check the wires going to the solinoid on the front axle and see if there is juice to it if so it is the solinoid or one of your hubs has gone out i have changed many of those hubs out on those older 4X4s.