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zukgod1
12-04-2006, 04:10 PM
Ok, I have a fuel filter/ heater assy off my 01 that I'm going to use on my little Toy project, The part is off a 01 that's why it's posted in this section.

I can see and figure out the water light no problem but I dont have a clue what to do with the heater.

Can someone tell me what terminals do what in there?

tks
dan

Billysgoat
12-04-2006, 07:56 PM
I'll get the service manual out and look it up for ya' Dan.

Billysgoat
12-04-2006, 10:09 PM
Okay Dan, here goes....

The fuel heater/temp sensor unir used on the FF assymbly on our trucks is NOT controlled by the PCM or ECM, it is a stand alone unit.

"When the temperature is below 45* (+/-8*)F, the temp sensor allows current to flow to heater element warming the fuel. When the temperature is above 75* (+/-8*)F the sensor stops current flow to the heater element"

In english, the temp sensor will "make" when it reads 45*F or below and close a circuit, this circuit is used to activate a NO relay which in turn supplies the amperage needed to operate the fuel heater. Once fuel temps reach 75ish the temp sensor will "unmake" and open the circuit, thereby returning the relay to the NO position and killing power to the heater element.

To find the correct terminal I think this will work, the FSM is very vague and only specifies "The two terminals in electrical connector at side of sensor" :bang Get the filter assembly outside or in the fridge or freezer to get it below 45*, find which terminals have continuity to each other, you should have two sets, one will be the temp sensor, the other will be the heater element which has a resitance of less than 1 ohm when cold. Write them down, now take the sucker somewhere it can get above 75* (I reccomend pouring the filter bowl full of steaming hot water from the faucet, hot tap water is usually 85* +) and see which set of terminals are no longer a closed circuit. That will be your temp unit :D

To wire it up go to the local dealer and get a repair connector that will fit it, run 12VDC+ to one side of the temp unit and out to a cont. duty, NO relay. Wire it so that this will activate the relay and provide power to one side of the heater terminals with the other terminal going to ground. The amp listing for the temp unit is 10A and for the heater unit it's 40A. Either a relay or a winch solenoid would be a good choice, they will serve the same purpose.

Confused yet?? LOL LOL I know you have enough know how to figure out the wiring Dan, but I wanted to include it for anybody else wondering the same thing.

zukgod1
12-04-2006, 11:58 PM
That is perfect! Thanks.

The factory dodge filter is a much better filter than the toyota filter system by a long shot not to mention the addition of the fuel heater.

Thanks again man I appreciate it greatly.

dan

Billysgoat
12-05-2006, 08:22 PM
My Pleasure Dan