Forum Discussion

3GageBoys's avatar
3GageBoys
Explorer
Jan 14, 2015

Losing Electrical Power when motorhomes engine is started.

Looking/Hoping to find someone that might have had this issue that can
help resolve this problem. The motorhome is a 2013 Thor Outlaw (Class A)
The problem my buddy is having is that the moment he starts the engine on the motorhome he will lose all 110 electrical power to the coach.
This will happen both when he is plugged into the shore power and/or
running off the generator. He has been on the phone with Thor and they have sent him a new inverter last night and he installed and tested that a few hours ago and is having the same results. He has full power
when the motor is not running. The only time that he was able to
correct the problem was when he disconnected all the batteries to the coach(House and Chassis) and when he tested it worked like it should until he shut the engine off and then restarted the power kicked off again. Thank you in advance for your time and effort in helping us get this problem resolved!!!

Thanks
Sid Gage
  • enblethen's avatar
    enblethen
    Nomad
    Jan 14, 2015
    There is no direct link between the 12 volt system and the 120 volt AC system unless everything is run through an inverter. Not likely!
    You are saying inverter, do you mean inverter or converter?
    A converter changes 120 volt AC to 12 volts DC.
    The inverter changes 12 volts DC to 120 volts AC.
  • 3GageBoys's avatar
    3GageBoys
    Explorer
    Jan 14, 2015
    wolfe10 - He losing all of his 110 power when the coach is started. He
    still has the 12 volt DC power.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Jan 14, 2015
    "he will lose all electrical power to the coach."


    All alternating current and all direct current?

    This is most interesting...
  • wolfe10's avatar
    wolfe10
    Explorer
    Jan 14, 2015
    A bad inverter in a motorhome will generally NOT cause complete loss of 120 VAC. Said another way, the inverter should not be powering the roof A/C. Does the roof A/C work?
  • 3GageBoys's avatar
    3GageBoys
    Explorer
    Jan 14, 2015
    Ivylog - That was my first response to him also. That tested out okay. He can switch back and forth between shore power and generator. The system just fails when the coach motor is started.

    enblethen - All batteries have been disconnected/checked for damage/re-installed
    with no issues to be found. I questioned him to see if he could test for back
    feeding from the engine alternator....

    Was just updated on the issue. He pulled the invertor out and hooked it up to another power source and failed to work. He was just informed by Thor that they may have a bad batch of invertors.... sending a different brand over night...
  • enblethen's avatar
    enblethen
    Nomad
    Jan 14, 2015
    I would verify polarity of the coach battery system. It is possible when the charge relay energizes, it trips out the 12 volt DC coach system.
  • Ivylog's avatar
    Ivylog
    Explorer III
    Jan 14, 2015
    My first reaction is to check the transfer switch but No 12V there on mine. So Back to the inverter but all of the AC power does not go through it on mine. Sorry but I do not come up with what is common to your problems if you are loosing all AC power. This could be "Very Interesting" when it's not my problem.

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