Being new to the 6.0, and diesels in general, is there an minimum ambient temp where the truck heater absolutely MUST be plugged in ? I hadn't run my '04 for a few days.. we had single digit temps and when I tried to start it yesterday (12 deg F) she cranked a little slower than normal but didn't fire once. The glow idiot light went out, I cranked for a few seconds.. tried it twice but didn't want to kill the batteries. Is this 'normal' or would you say I have to look for a problem with the truck??

Still love the truck.. but I'd hate to be parked somewhere not near a 110 volt outlet and not be able to start 'til the temps warmed up!

 

The truck needs more power to start.Have the batteries load tested. Replace the pair with 850cca,it should start into the -20sC without a problem.

 

I know this is a really old thread.. but here's the update..
Batteries were in poor condition. I replaced 'em and the PSD spins over faster than it ever has since I've owned it. Also.. the glow plug light goes out quickly. So.. if your beast is not starting well in cold weather, do not overlook something as simple as batteries.

 

Thanks for the update,it helps others that are searching for answers to their troubles.

 

Here is the master guide to most of the transport batteries that Exide makes under various brand names:

http://links.exide.com/pdf/exide_battery_specs.pdf

Here is the link to look up your battery:

http://links.exide.com/pdf/exide_battery_specs.pdf


The key is to look up the group size.. and then, within each group size, search for the most battery for the money.

 

I plugged in my 6.0 and it is interesting to note that the OE is 750CCA X 2.

The reason the OE batteries last longer is that by lowering the CCA from 850 to 750 in a same size battery case and using the same amount of lead, it is possible to use stronger lead plates (less spongy lead), and by doing so, make the batteries last longer.

With 2 batteries in parallel, you have effectively 1400 CCAs with 750s.

More CCAs at the expense of deep cycle life is not necessarily better.