Brake light weirdness Dodge Ram

[bobhustead]

On my '04 Dodge Ram, the brake lights come on (without depressing the pedal) and stay on when the engine is running. This does not happen when the switch is on and the engine not running. Brake lights work normally on depressing the pedal with the key out, with the switch in accessory position and with the switch on but without the engine running. I suspect an expensive control module has lost its mind. Any opinions?
Thanks,
Bob

 

[pdplot]

Check the switch at the brake pedal. There must be some free play between the pedal and the switch. There may be an adjustment if its touching.

 

[bobhustead]

The switch works as designed in ignition off, accessory, and ignition -on-but-engine-not-running positions.
Bob

 

[George_H]

They have a giant plug going thru the firewall. A little water or can get inside and cause all kinds of very strange things. I had an 03 that the dealer had for a long time before they figured it out. It had a different issue but I can see how this might happen.

 

[bobhustead]

A wire not on the wiring diagram was part of the group that ran to the brake light switch. This wire had a constant 6.5 volts. Cutting it and running a new jumper from the brake light switch to the relevant pole on the trailer brake control fixed all known issues. Forward control module and instrument cluster involved in these circuits (external lighting) are apparently behaving as designed.
Bob

 

[Deleted member 28051]

A little bit of water or can get in and cause all sorts of extraordinary things. I had an 03 that the dealer had for a long time before they figured it out. It was a different problem, but I understand how it could have happened. The forward control module and instrument cluster involved in these circuits (exterior lighting) seem to be behaving as intended. When the engine is not running, the switch works in the ignition off, auxiliary, and ignition off positions. Where did you buy your vehicle? I purchased it from truckexporter in UK], as the prices there are a little lower than on the market. So I purchased from them and have not regretted my choice.