Brake/ABS idiot light

[Mr. Hemi]

I know others have had to experience the same thing I have for the past few years, the Brake light and the ABS idoit light come on after switching from defrost to heat. They go out after a few seconds to a minute, sometimes occur after shifting the transfer case also. Is this a short or a vacuum problem? Seems no affect on the vacuum poer assist brakes. Saw a post on the lights staying on this past week. Also lost the funtion of the vents/bilevel control this summer, just waiting for a long list to take it in for the extended warranty. Figure the vacuum motor died??? Any pointers?

 

[Missouri Mule]

Mr. Hemi,

The switch for selecting direction of air (cold/hot) has vacuum lines attached to it ( also the actuators at the ac/heater unit).



Vacuum is also used to operate the fork on front axle to engage when 4 wheel drive is needed.



I believe you are loosing vacuum! You mite have one leak but possible you have two.



The brake/abs warning lights will come on for malfunction of either system which includes loss of vacuum.



Look for leaks in vacuum lines. Another possibility is vacuum check valves( I believe there are two) are bad.



If you lost only vent/bi-level I would think you have leak/ pinched/unattched vacuum line or bad actuator/leaking/pinched line to actuator.