nelsokelso Report post Posted February 9, 2013 I have a 2001 Monaco LE 38' that when the furnace starts the 12 volt interior lights dim momentarily. According to the Monaco tech the latching relay in the left front basement electrical compartment was the culprit. I changed this and still have the problem. I'm connected to a 50 amp service. New batteries were installed 9 months ago because they were bad, so I know this isn't an issue. . I had to replace the blower motor in the furnace last week so I know that can't be the problem. I'm looking for a location to check the voltage drop other than the blower motor. Any suggestions would be helpful. Thanks Share this post Link to post Share on other sites
desertdeals69 Report post Posted February 9, 2013 Check the amp draw on the furnace to see if in spec. Check battery voltage at the furnace and at the interior light circuit and at the battery. Any drop between the battery and furnace or lights probably means bad connection or too small of a wire. Share this post Link to post Share on other sites
nelsokelso Report post Posted February 11, 2013 Thanks for the info..a bad connection will be hard to isolate because all the interior lights are affected. I'll start the investigation and report. Share this post Link to post Share on other sites