Very little power to 4x4 actuator

96 Tacoma 3.4 ...5 speed, push button 4x4.....bought the truck knowing the 4x4 issue...all vacuum hoses are in good shape...I have vacuum to actuator on front diff...the other day all the sudden the 4x4 indicator light on dash lit up when I pushed the 4x4 switch...then it wouldn't work again...I pulled the plug off the actuator and put my test light on it to make sure I was getting power to the actuator.... The plug would barley light up my test light...any help will be greatly appreciated

 

Sub'd. Having similar issues and trying to trouble shoot, but will gladly listen to everyone's recommendations.