cruise control doesnt work

[aschrep]

so the cruise control doesn't work on my 2003 tahoe. computer controlled. the third brake light was out and I replaced with an oem led light still no cruise control. when I take a normal bulb and wire it into the third brake light cruise control works what do I do to get my oem third brake to allow the cruise to work.

 

[07burb]

How in the world are you testing the functionality of your cruise control and whether it works with different configurations with your 3rd brake light? If your 3rd brake light is in anyway affecting how your cruise control works you have some electrical problems and I'd suggest getting a professional to look at it.

 

[rockenthebowtie]

This may be a stupid question but did you verify the center high mount lamp is working does it light up when brakes are applied

 

[aschrep]

Well 07burb the 3rd brake light is how the TAC module knows when the brakes are applied to cancel the cruise just seeing if anyone had the same problem and a fix for the problem and yes rocken I did verify the brake light does work

 

[rockenthebowtie]

Do you have a aftermarket alarm... if not test the CHMSL supply voltage/stop lamp supply voltage circuit for an open or high resitance between the stop lamp switch and the TAC module the reason its not working with the factory lamp assy is because of the diodes its only allowing voltage flow in one direction the diodes are and electrical check valve and with the regular light the voltage can travel in both directions manipulating the TAC module