scratch that...........I thought yer truck was newer.................I guess I dont know on a 99.....there is no sensor on the air inlet on a 99


maybe its in the intake manifold ????


AIT sensor maybe...............Bingo I think we have a winner

AIT is back of the motor drivers side just below injector #6

Sometime today, I will try to find my service manual and have a peek for you Bia...

Ok I will check that I guess when it stops raining if not Im taking my headlights out lol

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ok thank you much.

With my luck its probably some rare sensor that is on back order for 6 months and cost 500.00 lol

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[lukesdiesel] The heater system consisted of the air-heater unit mounted on the intake manifold cover, the microprocessor mounted on the left side of the dashpanel, two relays on the left inner splash shield, and a temperature sensor in the intake manifold.

luke informed me of this so I guess its more than one spot that could be bad

IAT Sensor....(Intake Air Temperature) :ph::ph:

The more I think about it, this seems to be the problem.


Heres some info for diagnosing the sensor:

http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm

Give it a good cleaning with some electrical contact cleaner (or brake cleaner if you are in a pinch) and see what happens. This thing isnt real easy to get to - you will likely have to lay on the valve cover.

They are not expensive either...

The IAT sensor measures the temperature of the intake manifold. The ECM uses this sensor reading to set injection timing and adjust the air-fuel ratio. If the fuel mileage and power output of you engine seem low, some owners have found improvement in EGT, fuel economy, and power after cleaning carbon from the IAT sensor in at the rear of the intake manifold. Engine with exhaust brakes are particularly prone to IAT sensor fouling because soot is blown back into the intake during valve overlap. Smokingdiesel.com has an information page about problems caused by the IAT sensor.

The only tool you need is a 3/8" ratchet with a 6" extension and 13/16" socket.

The IAT sensor is found on the driver's side of the engine, almost at the back of the intake manifold.




Temperature
Resistance

30°
40K

32°
30k to 36k ohms

76°
13K ohms

77°
9k to 11k ohms

81°
6.87K ohms

122°
3k to 4k ohms

130°
4K ohms

167°
600 to 675 ohms

212°
600 to 675 ohms


Replacement Sensor:

Cummins PN 3408345

Dodge PN 05014197AA Sensor, Temperature (SEN, TEM)

here is a pic of the lil buger too

allright cool thanks alot now my headlights can live lol. Once it stops raining I will go outside and clean it up and see what happens. Hopefully thats all it needs

Let us know how you make out.....

Bia, Ive been thinking about this a little...There are two relays that control the grid heaters - they are on the drivers side fender. Im thinking that one of them is bad.

Intake Heater Relay

This is for a 12V I dont know about the 24V