Wiring issues in the MH.

Thank you, for posting back with the cure.

Finally got the RV out storage (we sure have had a long hard winter :( )

The problem with the lights/cruise ended up being a corroded brake/tail light issue. We replaced the whole light box and the mystery is solved.The brake light really does affect the cruise and kicks it off when the brakes/flasher are applied.

Thanks for all the help and suggestions.

Its almost always a ground problem. The TS switch is the last thing I'd tear into !

jimjr wrote:
...It's a 2006 Class C on a Ford E450 chassis.

See that emergency flasher button on top of the steering column? Start there.

Fill the well around the button with WD-40. Work that button up and down repeatedly until it loosens up and all the issues are likely to go away.

Let us know if it works.

What you have is a poor ground. LIKELY (But not necessarly) on the rear turn signals.

Here is what is happening:

The cruise control reads the voltage across the brake light switch, It wants to see 12 volt on the high side and zero on the load side of the switch.

If you have a bad ground on the tail lights and the common dual filiment lamps like a 1156 or the wedge based equivlent.. When you turn on the tail lights, power feeds back to the brake lamp circuit. When you use a turn signal power feeds back via the tail light elements to the brake light circuit via the other side.

And that kills the cruise.

I had a problem with the FRONT turn signal not grounding properly and it caused the same issue.

And when I got a new towed,, The ground connection on the socket for the towed (Motor home end) needed an upgrade as well.

Thankfully, though these things do tend to save me the cost of a hair cut.. Figuring them out IS within my skill set.

Thanks for the responses.

Sorry for the lack of info about the MH. It's a 2006 Class C on a Ford E450 chassis.

I would start with the basics, as was said the cruise control senses voltage in the brake light circuit to determine that you are stepping on the brake and so disengages the cruise control.

Start by observing the operation of the rear bulbs...hwat happens when you put on the turn signal? What happens when you put on the turn signal while your foot is on the brake? How the lights respond to instructions will give you an indication of whether there is a ground issue or possible a bulb issue.

Taking the steering wheel off and checking the stalks should be the last resort for this repair.

What chassis? Can't give anything but guesses without that info.

X2...What he said
Your going to have to take the steering column apart, to replace that switch or the lever that contains the cruise control wiring,
Start by removing the steering wheel

I'd view the operation of the stop and turn lights for a clue. It may be a bad ground but more likely you may have an issue with the turn signal sw in the steering column. When a turn signal is operated, the sw disconnects that side from the brake light for the other side so as not to flash both. Yours may be feeding back into the brake wire to the pedal sw and cancelling the cruise control.