This is a new twist on the IAT mod that gives your Magnum engine a few more ponies. This mod was developed to fix the two issues that the standard permanent moving of the IAT causes; lower MPG, & clogging of the catalytic converter sooner.

Parts you will need to complete this mod:
Double-Pole-Single-Throw Switch
6 Foot of 3 conductor wire 20 gauge
New IAT Sensor
*Rubber grommet, simple way to install the IAT into the new location.
*IAT wiring harness pigtail
*K&N Air Filter Part # E-1100 Recommended for optimal HP gain with this mod.
*Heat Shrink tubing
*Optional but recommended for the professional/show look

Tools needed:
Drill and bits, unibit
Wire Strippers and wire cutter
Soldering Iron or Gun with solder
Zip Ties
Screw drivers as needed
Ratchet and sockets as needed
Heat gun or hair dryer (Do not recommend using lighter or matches near your engine)
Black electrical tape

Instructions:
Always disconnect the battery when doing any electrical work!

Here is the wiring diagram I designed:

Substitute the gray wire for the white wire listed below in the soldering instructions.

First pick a location as to where you want the switch to be mounted. (I chose the electric mirror control location due to my van not having that option) Be sure that there are no obstacles behind where you plan on putting them and that they are in easy reach as you drive the vehicle. Once you are sure of where you want them then drill the hole the size of the switch.


The wire I used had 4 conductors (red, green, white, black and shielding) I cut the shielding and black wire off. On the switch I soldered the green to the up side of the switch so that when the switch is in the down position it would be using the original IAT sensor. Then the red wire I soldered to the lower terminal of the switch so that when the switch is flipped to the up side then the new IAT sensor will be working. I used the white wire to bring the PCM power from the harness to the switch. I cut off the black and shielding wire from this new wire.


Remove the air cleaner housing so that you can mount the new IAT sensor. I drilled mine into the snorkel and used a grommet to hold the sensor in place. Be sure not to over drill or the grommet will not fit snuggly with the sensor pushed into it.

I also used a dremel tool with a grinding stone to remove the burrs from inside the snorkel. Now mount the grommet and new IAT sensor.


Take the 3 conductor wire bundle and feed it through the Firewall, You can notch the Throttle Cable Boot or carefully drill a hole and use a wire grommet and push the wire through it.




INSIDE route the wire to the switch and be sure it will not get pinched or yanked, leave a about 6 inches extra to work with (more if you found a good but tricky place to mount your switch). In the engine bay route the wire along the firewall across the PCM and down towards the right side of the engine near the original harness. I brought mine behind the alternator.

If your new wiring has the shielding you can use it if you wish. If you choose to only attach one end of it, not both. I chose to connect mine to the alternator body ground terminal (see above pic). The shielding will stop most if not all electrical interference from ignition, alternator and such. THE SHEILDING IS NOT NEEDED FOR THIS MOD.

I looped my wire below the alternator and bought it up about 4 inches. I cut the original IAT harness. I then soldered the wiring as follows starting with the new wiring harness:
White wire to the Black with Red strip still attached to the original engine harness
Red wire to the new IAT sensor
Green wire to the old IAT sensor
I then took the Black with Blue strip wire (which ground to the vehicle) and connected it back to the old IAT harness and the new IAT negative wire.


I tested the connection back to the switch to be sure all was working well.
Test using a ohm meter/setting from the white wire to the green and red. It should indicate that the connection is good from the white to green when the switch is in the down (economy) position and nothing between red and white. Then test the white to red and it should work when in the up (power) position and should be no reading when connected to the green wire. On my new wiring harness it had a shielding wire I attached this to the alternator body ground.


After you have tested the system apply the heat shrink tubing and/or liquid electrical tape. For the factory finish look I applied electrical tape to the new wiring. You can even use convolute wiring cover for parts of the new wire for a really nice factory and show vehicle look.


Reattach the air cleaner and connect both the new and old IAT sensors.


Don't forget the K&N air filter for best performance with this MOD.


Reconnect the battery and test run the engine. Enjoy your new Switchable IAT MOD.

 

So what is the purpose of doing all of this as opposed to just relocating the IAC to the new location?

 

While doing my research about the mod showed me two issues regarding just relocating the current IAT sensor. These issues I did not want the hassle of, and only when taking off, passing, or pulling very heavy loads would the mod be of use. Rest of the time driving the mod is not needed. By switching between the two sensors the driver gets the best of both, power when needed, yet fuel economy the rest of the time.

 

What years is this applicable? What does the IAT do?

 

The Magnum series engines were first intoduced in 1992 with the 3.9 and 5.2L engines. The 5.9L Magnum was introduced in 1993. These engines were used at least through the 2003 editions of the vans.

The IAT (Intake Air Temperature) sensor is used on most all sequential multipoint fuel injection (SMPI) engines.

This mod should work on any IAT that is mounted in the intake manifold verses mounting in the intake duct before the throttle plate. If you engine has the IAT in the air intake ducting then this mod is not needed.

 

i know its old, but is the purpose of this mod to trick the pcm to thniking it has a colder air charge? thus giving it more power, by dumping more fuel? and from what i read you said this can be done on all magnum engines, im wondering because im thinking i might do this to my 00 ram 1500 with the 5.2

 

Yes, and yes.

It is not extreme amount of power that the engine gains but it is noticeable when under heavy acceleration such as getting up to highway speeds. Is the power there the rest of the time, I do not know for I do not have any way to measure it. I mainly run my van in Economy Mode. When I tested the mod I found it working by putting the van on to the highway entrance ramp accelerating up to 70 and flipped the switch into Power Mode and felt the engine get a little boost. Did not notice the boost any other time. Will try some more testing when I get a tachometer installed in the next 6 months or so.

 

im planning on doing a diy air intake, and i think ill do this same mod( i can let you knwo what i find out as far as power all the time, i have a factory tach, so you could possibly get results sooner, but i dont want to mess with my factory intake, so im gonna do it with my homemade one. lol.

what wires do i connect what to, on a 2000 ram 1500 4x4 with the 5.2?

i want to make it right the first time.

thanks in advance

 

Here is the wiring for your truck's IAT sensor. The Black/Red wire is the one that you want to tie into. Cut this one and run from the harness back the power to the switch center post, for this is the hot wire in.

The Black/Lt. Blue wire is the ground for the sensor, hook both sensors ground side to this wire.

When you get the new sensor it does not matter which lead you use as ground and which you use for the positive side.

 

thanks. im gonna do this once i get my intake made.