Gibson furnace cycling 2,3,4 times before starting
Hi, I have a gibson m#KG6RK 072C-12A s#KGA021204267.natural gas.I've cleaned the flame sensor,that seem to work for a day with the furnace starting up on the first try.then I inspected further and found some wires that melted on the inducer\flu parts.so I cut out the bad part of the wire and reconnected them ,that seem to work for about a day.I did find a ground wire screwed to the inside of the furnace that wasn't hooked up to anything and it doesn't look like it was ever hooked up to anything.then I check to see if it had a good ground and the copper wire from the fuse box was grounding the switch box that connects to the furnace,so I'm assuming that the steel casing from the switch is grounding it properly.so sometimes the furnace tries five times to start and it doesn't,which gives me five flashing lights ,meaning (check ground).now when the furnace attemps to start I hear the inducer making a weird noise.I can't explain the noise other than it sounds like its vibrating.do you think my flame sensor is bad is there a way to check the resistance with a analog testing meter.I hope I left enough info any help will be greatly appreciated.thanks,greg