Brake light switch activates running lights and interior lights

[Thump]

As the title states, whenever I press the brakes, my running lights and interior light come on. However, they don't activate when I turn on the switch for them, only with the brake light. Am I correct in assuming this is a short somewhere? I've consulted the wiring diagrams but no dice.

 

[chengny]

Am I correct in assuming this is a short somewhere?

Yes. The cross connection is probably in the wiring harness that runs up inside the steering column. As a test try this:

Locate the brake lights switch - the wires to it will be white and orange. Cut the white wire. Make the cut in a place that will allow for an easy re-splice.

Step on the brakes and observe whether the problem goes away.

 

[Thump]

Yup, that did it! White wire disconnected killed the lights!

 

[chengny]

Well, you know... I wouldn't get too excited.

True, you have identified where the problem exists, but you still need to make the repair.

If you're lucky, the short - from the brake lights to the parking lights - is in the actual MFS (multi function switch). If you are not lucky, it is in the wiring - specifically the group of wires that runs up the column.

If you have a tilt steering wheel, try positioning it at either the very top or bottom - sometimes that will disconnect the short.

As far as why the dome light illuminates when the brakes are applied - your guess is as good as mine on that one.

 

[Thump]

Thanks for your advice man. I was able to find the mess of wires that were causing issues. There were three or four wires cut and taped together (very poorly I might add) under the dash that were causing the lights to come on.