Does anyone know what the amp draw is on the stock fuel filter heater? Mine is leaking really bad. I am going to tap it and plug it with a brass plug. I want to install a fuel filter heater blanket and I would like to use the stock heater wire to run the blanket. The blanket I'm looking at draws 4.2 amps.

 

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength

I'd go with something like 12ga(or thicker) though, just because I've got plenty around.
5a isn't much.

 

We'll I guess if I go by the wire size alone the stock heater wire should handle it because according to the chart a 22 gauge wire handles 7 amps and the stock wire is heavier then that. Still would like to know exactly what that stock filter heater draws. Maybe I'll put a multi meter on it tomorrow and see what it reads.

 

fuel filter heater element = f2tz9j294a

http://www.ebay.com/itm/f2tz9j294a-Ford-6-9-7-3-Diesel-Fuel-Heater-f2tz-9j294a-Racor-Element-RK22010-WVO-/181240601942?pt=Boat_Parts_Accessories_Gear&hash=item2a32c81d56
description says: 12v & 150w so if that's accurate then =
watts (150) divided by volts (12) = 12.5 amps

 

Thanks! That is exactly what I needed to know. One more question, does anyone know if the wire going to the stock heater is always powered when the truck is running?

 

No, only powered when high idle and cold advance are powered, i.e. under 112* engine temp.

 

Alright. Sounds like it will work just fine.

 

Check again, at least on mine its always powered so long as the key is on.