IAT Resistor Mod--Which 2/3 wires?
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IAT Resistor Mod--Which 2/3 wires?
Short story: Why does the IAT have three wires? Using my 2-wire IAT bypass resistor module, which two do I need to use?
Long story:
For kicks, I just bought a $25 "Performance Module" off eBay, supposedly for my '99 V10, though most likely just generic. It is supposed to get you more HP while saving gas by crimping in parallel with the IAT. Okay, so I'm realistic, I know that it'll probably be just one or the other, and probably not much difference either way... But I figured it can't hurt anything.
Anyway...
My trusty voltmeter shows a resistance of about 4k ohms, which, since the IAT will still be hooked up, will still allow the ECM-read temp to change somewhat (i.e if the IAT at temp reads 30k, in parallel with the 4k module will make about 3.5k total, or the IAT reading 4k in parallel with the module will make about 2k).
I'd like to try this out, but the IAT has three wires--which two should I use?
Hell, if anyone has any info about min/max resistance values the ECM will still see in range, I might just try some Radio Shack resistors and hook up a 3-way dash switch for Economy (bypass IAT w/resistor for high-temp/lean fuel), Standard (IAT wired as stock), and Power (bypass IAT w/resistor for low-temp/rich fuel).
I'd love to pass along my findings!
Long story:
For kicks, I just bought a $25 "Performance Module" off eBay, supposedly for my '99 V10, though most likely just generic. It is supposed to get you more HP while saving gas by crimping in parallel with the IAT. Okay, so I'm realistic, I know that it'll probably be just one or the other, and probably not much difference either way... But I figured it can't hurt anything.
Anyway...
My trusty voltmeter shows a resistance of about 4k ohms, which, since the IAT will still be hooked up, will still allow the ECM-read temp to change somewhat (i.e if the IAT at temp reads 30k, in parallel with the 4k module will make about 3.5k total, or the IAT reading 4k in parallel with the module will make about 2k).
I'd like to try this out, but the IAT has three wires--which two should I use?
Hell, if anyone has any info about min/max resistance values the ECM will still see in range, I might just try some Radio Shack resistors and hook up a 3-way dash switch for Economy (bypass IAT w/resistor for high-temp/lean fuel), Standard (IAT wired as stock), and Power (bypass IAT w/resistor for low-temp/rich fuel).
I'd love to pass along my findings!
Legend
Joined: Jul 2007
Posts: 7,843
Likes: 13
From: DFW, Texas
You can't manipulate the IAT alone. The IAT works with many other sensors (most closely the MAP sensor) to adjust fuel trims. When you initially hook up the resistor, you may notice a slight performance boost. As soon as the PCM figures out that the IAT numbers don't jive with the numbers form the other sensors, it'll toss the IAT numbers, probably throw a CEL, and run off default tabled values stored in the PCM. Since these tabled values aren't as ideal as real world conditions, you'll be running less than optimal conditions and more than likely just waste fuel. The Mopar computers are the pickiest of the Big 3 for having things just right, trust me, I've been fighting an issue for the last 3 months that won't even throw a CEL to point me in the right direction.
I know you're not going to want to hear this, but you just wasted $25. Please don't hack up your IAT harness and waste even a minute of your life force installing it.
I know you're not going to want to hear this, but you just wasted $25. Please don't hack up your IAT harness and waste even a minute of your life force installing it.
