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MarkandJaneAnn's avatar
MarkandJaneAnn
Explorer
Jun 05, 2017

Brake Lights

Good day everyone, I live in Nova Scotia and technical assistance is not great in my area. My 2003 Newmar gas is experiencing electrical problems that I hope someone else has seen or is technically able to provide assistance. I noticed I had no brake lights so I checked the grounds and bulbs and fuses all good. I pulled the connector just as it enters the back and up to light inside of the rig. Metered the brake wire and have 12 volts, I can also hear an electric motor running under the hood, I assume some kind of brake assist??? I decided to jump the connector in case there was corrosion inside. The second I completed the red wire brake circuit to the brake lights the electric motor stopped and no brake lights,it also did not start up after removing the jumper??? let go of the brake pedal and re applied then the sound of the motor started again. I get the impression the two issues are related??I put it all back together scratched my head and have no way of getting it to a repair shop which is at least 2 hours up the road. Any assistance would be greatly appreciated.
Class A
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 06, 2017
    You blew a fuse

    The motor is in deed a brake booster (Hydraulic pump in fact)

    The motor is activated when two things happen.. ONE< no pressure/flow sensed in the power steering line from the power steering pump (IE: Motor not running) and 2: Brake pedal pressed.

    When you jumpered the wire,, You blew the fuse for the brake lights.
  • MarkandJaneAnn's avatar
    MarkandJaneAnn
    Explorer
    Jun 06, 2017
    I do still have hazards and turn signals, I also confirmed the fuse is good. While stewing over this most of the night I wondered if the relay for the boost system might be at fault (weak). I will go to the only automotive store (NAPA) here and check on a replacement! I could drive it up to the city I guess, if i put the hazards on and step on the brake they stop flashing and would simulate brake lights. I will keep you in the loop.
  • fairway2002's avatar
    fairway2002
    Explorer
    Jun 06, 2017
    Sounds like you have a short. Most light fuses are self reseting Longer ones in your panels
  • STBRetired's avatar
    STBRetired
    Explorer
    Jun 06, 2017
    If you have hazards and turn signals, then the fuses and wiring to the lights are fine. That leaves 2 possibilities. the turn signal switch and the hazard switch. On my MH they are all in the same unit. Not sure about the 2003 version. The switch on the brake pedal seems to be working as it energizes the booster pump when you step on the brakes. You could also check the brake/turn pins in your 7 pin trailer connector. It is a separate circuit from the coach brake lights.

    I had a similar issue on my 1999. The MH brake lights worked fine but the right brake light in the trailer connector did not. The turn signal worked ok. It turned out to be the multi-function switch (turn signal/hazard/wiper switch). I had called Newmar and they told me that was all Ford wiring. Ford was less than forthcoming with information unless I wanted to buy the service manuals. Finally found a Ford mechanic that enlightened me about the 2 separate circuits and what to check for.
  • Jim's avatar
    Jim
    Explorer
    Jun 06, 2017
    When my brake lights went out, it turned out it was because the relay under the hood was in bad condition. The relay eventually failed outright but before that was a few weeks of intermittent craziness. Rust, corrosion, even a wire hanging by a thread seemed to have caused it. Once it was replaced and the corroded terminals replace with new, all returned to normal. It was giving odd symptoms that would change over time because of it's poor condition.

    Also have an auxiliary pump under the hood that creates a vacuum that operates the doors for the dash comfort vents. Heat, straight vent, AC...that sort of thing. Turns on and off at seemingly random times when there's a leak in one of the hoses.
  • MarkandJaneAnn's avatar
    MarkandJaneAnn
    Explorer
    Jun 09, 2017
    Well drove up to the city found a replacement Relay for the Brake Boost System and no luck. Looks like I will be crawling around under the doghouse for a few days. Thanks everyone for trying:(
  • MarkandJaneAnn's avatar
    MarkandJaneAnn
    Explorer
    Jun 30, 2017
    Hello everyone, I scratched my head for hours going over the wiring schematic and narrowed it down to the only thing that controlled both brake assist and brake lights. the brake switch mounted to the pedal. Metered the wires and found one dead with brakes applied, changed the switch and boom problem solved. Thanks everyone for your inputs! Cheers and happy travels!! Mark and JaneAnn

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