Zerostart 3100109 Engine Block Heater for Buick, Chevrolet, GMC, Hummer, Isuzu, Pontiac, Saab, Saturn, Oldsmobile, 28mm Thread | CSA Approved | 120 Volts | 400 Watts

It is summer right now and I tried to see if it would start heating (after installing it) and was disappointed that it didn’t seem to work. So I did a continuity check on the electrical cord and one of the wires indicated open. I finally saw the tag on the cable that said it works only when it senses the ambient air temperature is less than 0 degrees F. So no problem. Just wish they would have put that info in

Not understanding does this only work in specific temperatures? I plugged mine in before installing and its not warming up?

Did not function it was installed by a licensed auto mechanic and the first time it was plugged in it popped the breaker in the house and has not worked since! There is nothing major as far as electrical, like plugging in a lamp! So there is nothing that can be said about a mess up with the installation