Thinking of getting 07 Dodge 3500 off lot before new pollution laws go into effect,have 2 7.3s Ford, both have engine block heaters, but the 2 Dodges on lot don,t have it, does cummins engine not need option in NJ? Is it easy to install on existing truck, it is only a factory $10 option.  

Block heaters are nice but with a cummins they are not essential.  It was 0 degrees here in Utah the other day and I forgot to plug mine in and the truck started right up.  No problem at all.  The nice thing about heaters are the coolant is warm allready so you're cab heat works faster.  

Thanks for the info on the block heater for the cummins.  

On the subject of block heaters, has anyone had their's fail? Mine doesn't seem to be working. I haven't taken it apart yet to check the continuity of the wire lead to electrical plug, or the heat coil itself. Didn't know if anyone could shed light on it.  

2004 dually. In canada -8 and truck is fine to start but if you plug it in it will defrost a LOT FASTER and warm up a lot quicker but the dealership says it is not essencial just nice for cold mornings -5 ish  

Well after spending the last 30 some odd years of my life on diesel engine in every from from 2 cylinders to V 16 A block heater makes a lot of sense. Diesel runs on heat. Starts with no heat are terrible on bearings, straters ,altenaters,batteries,and electrical systems.Try starting semi in 0deg. weather with out block heater. When you crank your Cummins engine up watch your amp gauge go up and down as manifold heater goes off and on.In my opinion for what its worth buy and use block heater as Cummins likes to sell parts Dodge does too!!!! To check block heater which is same as electric stove element. Use ohm meter check resitance on plug and then remove plug at heater and check ohms if not open then check cord if ok then remove and replace heater  

Actually the new cummins manifold heater will come on reguardless of engine heat.  It is set to come on below a certain temperature and engine speed.  Block heaters only help the actual temp of the coolant in the block.  

A certain "air temperature" is what I meant to say.....I believe it is below 40 degrees or there abouts....  

Im a tech at a dealership and all of the cummins come with the block heater installed but the ten dollars is for the cord to plug it in the block heater is located under the exhaust manifold toward the front of the engine  

The really good news to all Cummins have the block header, just not the cord. They also sell just the cords on ebay! I don't know what the dealer would charge after truck is on the lot as opposed to ordering it from the factory. Just a thought.  

I don't know what the weather in NJ is like but in Alaska the block heater is a must.  I also have an oil pan heater and a battery heater as well.  We've had weather colder than 40 below zero and my truck has always started right up.  On the days its colder than 40 below, I've had to run the truck for an hour before it would warm up inside.  I've seen other guys who didn't plug in during extreme cold weather and their trucks wouldn't start.  I've always plugged in when it is 5 above or colder.  

Up north in Canada,we can get down to -40,so I run 0-30 oil and also have my block heater on a timer...set it to run about 4hrs. Cold starting w/o block heater is hard on diesels...1998 12v,e/c 4wd