I don't have defrost when the engine is running. I do have defrost with the key on and no running engine. I also don't have 4 wheel drive . I do have the brake/abs light on all the time. I've check the lines for leaks and found nothing with a hole or a crack. What's next Dodge experts?? I need to add that there is vacuum in the engine compartment and down at the 4x4 actuator.

 

Check harder, you have a vacuum leak, could be anywhere in the system.
Common place is at the cruise control actuator under the battery.

 

thanks for the diagram. I did add on my post that I have vacuum at the actuator but no 4x4 and under the hood. I will check the cruise control next. Would a bad actuator be the leak? I can turn the diaphram actuator alittle.

 

Battery acid will definitely eat the actuator enough to leak.

Easy way to see if you have any leaks is to run the engine then let it sit for five minutes.
Remove any vacuum hose, it should hiss, if it doesn't you have a leak.
A leak free system will hold vacuum for hours if not days.

A$20 hand vacuum pump with gauge from the auto parts is the best way to test individual circuits to chase down a leak.

 

I did see a couple of holes in the metal actuator body. Are they suppose to be there? I just got a new actuator for the 4x4. I will replace that tonight. I'm selling the truck and want it right. Thanks

 

fix the 4 wheel drive. The actuator shaft was froze up. May need to replace the heater control module next. The cruise actuator looked good.