With the colder weather around the corner, have to checked my 04 F350 to make sure I have the block heater cable (which it does), I have checked to make sure it works and as usual it does. My question is, how many amps does the block heater use, I will probably have to use my 100ft extension cord to reach my truck, and the best amps I can get for that length is 15 amps. If the heater is way less than 15 I'll be fine, if it's more I will have to figure something out.

 

Approx. 8.3 amps

 

I have read in the past it need to be connected to a 20 amp breaker. Don't know if this is correct. Just throwing it out there.

 

Jonarmy I'm in about the same position you are I use a 12 gauge cord "i have use a 14 gauge but perfer the larger 12" mine runs off a 15 amp breaker I haven't had any trouble trowing breakers yet I've had this set up on 3 diffrent trucks for the past 7 winters a 94 f450 7.3 a 98 f800 5.9 cummins and now my 03 f250 6.0 all with no issues