Iat/iat2

[DTUB]

Why are my IAT's reading backwards? Idle is 165 and wot is 6 :confused: :confused:
Am I using the wrong sensor?
03/04 Cobra Map / Iat that goes in the intake # 2R3Z-9F479-AA
Pig Tail # 3U2Z-14S411-SSA
Gray / Gray Red wires from MM Maf
What did I do wrong here. :banghead:

[Bradley G]

I was told to use the temp sender from an F-150 Lightning.

[justbob]

I imagine Bob already adjusted for the new location. I can't remember what part number Jerry sent me. Your IATS should average between 30-40 degrees above ambient temps ALL the time though.

The wires you tapped into on your MAF should be both the outside wires (Grey's IIRC) and it doesn't matter which wire goes to which.

[FordNut]

It is wired wrong. If you are using the Cobra sensor polarity is important. I believe the correct wiring is posted in the Eaton Conversion Parts List thread.

[SmokdMercRauder]

I have tried all differnet ways with the iat2 sensor and have had no success...:(...imma prob go with the lighting sensor soon..

[FordNut]

Somebody else had the exact same problem and it was wired wrong. If you change to the other type sensor you will have to drill and tap the manifold.

[burt ragio]

If you wirered it bolth ways with same results you could have a bad sensor change it out.

[DTUB]

I reversed the wires and now it reads between 197-200.

[Zack]

I reversed the wires and now it reads between 197-200.

Either the IC pump is not working, the hoses are kinked, or there is air in the system.

I bet its slow as sludge with IAT's like that.

[DTUB]

Shes a pumpin water like a garden hose. I'm getting these temps now with the motor off too so I guess its time for a new sensor. These are cold motor readings also.

[SmokdMercRauder]

This boggled my mind for a while...when it was on the dyno we tried a different sensor with no luck...i tried a few ways then..but not as many as i have recently...

[FordNut]

Still might be a wiring problem. The Cobra sensor has 4 wires, two are for the IAT and two are for the MAP.

[DTUB]

The map seems to be working fine so maybe I fried the IAT by wiring it backwards?

[FordNut]

I believe the MAF wire that was on pin 6 has to go to the IAT sensor pin 1 and the one that was on the pin 1 of the MAF goes to pin 4 of the IAT sensor.

http://www.mercurymarauder.net/forums/showthread.php?p=908712&highlight=pinout#post908712

[DTUB]

I've tried the wires both ways now and end up with 165 or 200 with the motor cold so I'll put in a new sensor this weekend and see if that cures it.

[SmokdMercRauder]

I've tried the wires both ways now and end up with 165 or 200 with the motor cold so I'll put in a new sensor this weekend and see if that cures it.
Well let me know the outcome..Cause i'm in the same boat as you...lol

[justbob]

I must have the Lightning one as I only have two wires and was told that I couldn't screw up the order in which they are hooked?

[DTUB]

Well I just threw another sensor on it and I get the same readings.

Rechecked the wiring. Gray wires to pins 1-4 on sensor. Tried switching wires and goes from 164 to 192, this is with a cold motor too. So one way is 164 and drops as you give it throttle and the other is 192 and doesn't move. Anyone else running the Cobra IAT?

[bob6364]

Just so i understand you snipped the 2 outer gray wires from the maf 1 plain gray the other gray with red stripe and attached them to iat2 right?

[DTUB]

Yes, Gray / GrayRed pin 1-6 to pin 1-4 on sensor.

[justbob]

My sensor only has 2 wires?

[DTUB]

Yea, I think your running a different setup though.

[FordNut]

Attached are a couple of drawings from the manual. The connector view clearly shows that the pressure or temperature signal is pin 1 and the ground/return is on pin 4. However, it wouldn't be the first time I've encountered an error in the documentation. Try switching the signal wires by leaving the gray/red (gnd) wire on pin 4 and connecting the gray wire (IAT signal) to pin 3. According to the drawings pin 3 is the signal for MAP but it is possible the documentation has the signal names swaped.

OOPs, pdf are no longer allowed for uploads.

[bob6364]

Basic connections are:
From MM > To Cobra
MAF P1 Gy/Rd > MAP/BAP/IAT2 P4 Gy/Rd Signal Return
MAF P6 Gy > MAP/BAP/IAT2 P1 DB/LG MAF Signal
EGR P2 Bn/Wh > MAP/BAP/IAT2 P2 Bn/Wh Reference Voltage
EGR P3 LB/Rd > MAP/BAP/IAT2 P3 Rd/Ye MAP Sensor Signal

[FordNut]

Basic connections are:
From MM > To Cobra
MAF P1 Gy/Rd > MAP/BAP/IAT2 P4 Gy/Rd Signal Return
MAF P6 Gy > MAP/BAP/IAT2 P1 DB/LG MAF Signal
EGR P2 Bn/Wh > MAP/BAP/IAT2 P2 Bn/Wh Reference Voltage
EGR P3 LB/Rd > MAP/BAP/IAT2 P3 Rd/Ye MAP Sensor Signal

According to the documentation in the service manual that would be correct, but try this just for S&G:

From MM > To Cobra
MAF P1 Gy/Rd > MAP/BAP/IAT2 P4 Gy/Rd Signal Return
MAF P6 Gy > MAP/BAP/IAT2 P3 DB/LG MAF Signal
EGR P2 Bn/Wh > MAP/BAP/IAT2 P2 Bn/Wh Reference Voltage
EGR P3 LB/Rd > MAP/BAP/IAT2 P1 Rd/Ye MAP Sensor Signal

[DTUB]

BINGO :banana: I swapped maf gray to sensor pin 3 and egr pin 3 to sensor pin 1, now getting 100 for temps and aeroforce gauge reading -21.0 for vacuum which it wasn't reading anything before.

I was sure I had it wired correctly the first time but sometimes you just never know. THANKS :beer: THANKS :beer: THANKS

[bob6364]

Good call Fordnut...i'm running the 2 wire sensor so never ran into this wireing saffu