My wife and I bought a 1999 Dodge Intrepid a while back, had it for about 4 days. She drives it to and from work. She came home and pluged it in for it was going down to -40c that night [ got to -50c ] Went out to start it the next day and "-NADA-, everything worked but no start or sound". took the battery out ,{it`s brand new}and charged it up but still no\go.When the relays are crossed it does turn over , everything works,including the ign\switch. I`m at me witts\end PLEASE HELP

 

First of all, I assume your block heater are defective because I never see a car not starting when heated all the night long...