Been reading the block heater posts. One thing not mentioned very often is the defrost setting.

Proper shutdown = defrosted windshield.

When you turn off the heater fan in a Ram, all the HVAC doors close. So, keep the blower "on" and switched to defrost. The doors will stay in that position when you turn everything off. (If you don't believe me, turn the ignition on and turn the blower on and off and listen for the doors to slap open and shut.) Plug in your truck and enjoy the open patches of ice or snow. Most of the time the wipers are even thawed.

Due to convection, the block heater will cause a slow circulation of fluid and push warm coolant into the heater core.

Lots of questions about how long to run the block heater. As long as you need to. Get a cheap timer thats rated to 15 amps and try 4 hours. Adjust from there. Electricians help me out here. 750 watts is around 7 amps so double for protection? Plug the timer into the wall and run a short cord to the truck. Only concern is boiling the water out of the coolant. Sneak up on the heater and you'll hear it boiling around the element. So check your coolant concentration once in a while depending on how much you run the heater.

Finally, before anyone call bullarky, try it. Beats putting cardboard over your windshield!

 

Great post, to leave the blower on and the selector on defrost to utilize the convection of the block heater,,,,,

if the load is as you say @ 750 watts then a timer rated @ 15 Amperes is is a good idea,,,, and should be fine for periods of 4 or more hr. with no trouble,,,,

A # 14 guage wire extension cord will be OK to about 100 ft or just a bit more on the 7 amp load, wouldnt go any smaller or farther