Yeah, I know I bought a truck that guzzles gas and I've added things to it that takes it down even more. It like buying a truck knowing the mpg will suck and saying "I can buy a CAI to help with mpg" and somehow using the stock air filter and tube to do it. Have MDS and was just trying to see if there was a way to use it more. I have found with so many things the factory setting are VERY modest and the truck can do sooo much more. Take exhaust for example, the truck comes with a restrictive exhaust setup. We can change the muffler, remove resonators and get a little better mpg and more hp. so why doesn't it come from the factory like that? Because some out there would complain about the noise(crazy bastards...it sounds awesome with beefy exhaust). Make the MDS come on at a higher speed when there is more of a load will make the truck feel like it has a lot less power hence making some people say "The HEMI doesn't feel like it's that powerful of an engine at highway speeds and not worth the extra $$$s or hype" thus hurting their sales.
makes sense?

 

I saw this "how-to"in another forum. I haven't tried it myself, but it looks like a good write up. Let us know if anyone tries it out.

[align=center]This is How to add a MDS light to your dash[/align]
[align=center]This will work for the 2006 - 2008 Dodge Ram as long as you have MDS[/align]
[align=center]The light will come on when the MDS is active (running on 4 cylinders)[/align]
What you will need:[*]Green LED from Rat Shack 276-271[*]soldering iron[*]rosin core solder[*]drill with 1/4" drill bit[*]about 10' of wire 22 ga[*]wire stripers[*]wire terminal crimpers[*]a 1/4" ring terminal for 22 Ga (red)[*]Inline wire tap for 22 ga (red)[*]pliers to sqeeze splice[*]2" of shrink tube for the 22 ga wire[*]1/4 x 1 and 1/4 bolt and nut

First thing is to find the Brown/Orange strip wire coming from the C3 connector of the PCM located on the fire wall behind the air filter. The top connector is C1 and C4 is the bottom one. The wire bundle from C3 comes over to the fender and up, which gives you good room to pull the BR/OR wire out. Using the wire tap splice in the wire your going to run (Attachment 1).[*][*][IMG]local://upfiles/64820/23E28871B7934D739080224C7591439C.jpg[/IMG]

Now run the wire along the top of the engine compartment and I ran it through the existing tie straps that hold the existing bundle (Attachment 2).[*][*][IMG]local://upfiles/64820/96FB649811DE4F22A399524BEF4BB505.jpg[/IMG]

Then I poked it through the firewall through the grommet that has the hood release cable but you can go through where ever you want (Attachment 3).[*][*][IMG]local://upfiles/64820/00D5E56564D64383B2A11FD1C8F63F29.jpg[/IMG]

I used a small plastic plug that is in the drivers side knee booster to mount the light in. I could pop it out with out removing the whole panel. Drill a 1/4 hole in it and you might have to ream it a bit and debur. Mount the led and then side a 1" piece of heat shrink over the wire and then solder the red led lead to the wire. Then solder a short length of wire to the black ground lead. Slide another heat shrink tube over that solder connection and shrink with heat, and do the same to the red wire tube. I like to use a portable butane powered soldering iron for this kind of work and as a added bonus, you have a hot exhaust from the iron to shrink the tubing. Now crimp the 1/4' terminal end on the ground wire. The 276-271 LED has a internal resistor to make the install easier. If you hook it up backward you will not hurt a thing, It just will not light up (Attachment 4).[*][*][IMG]local://upfiles/64820/AAA839705EBC4FE1A13591B2680ED0CF.jpg[/IMG]

Reinstall the plastic panel plug and then go under the dash and attach the ground. I used a 1/4" hole in the large cast aluminum part that supports the steering column and the 1/4" nut and bolt (Attachment 5).[*][*][IMG]local://upfiles/64820/6C136310317F4BF0AD9DBB8CF23C53AD.jpg[/IMG]

You can add a small toggle switch inline to turn off the light. It doesn't matter which wire you put the switch in. Since its mounted so low it doesn't shine in my eye and the steering wheel blocks it for the most part. I have been using it for a few days and here are a few observations - MDS will kick in at a slow speed, accelerating from a stop slowly it will come in at about 10 mph and I could accelerate to highway speed without it dropping out but you better not have anybody on your bumper. At 70 mph it will still kick in but I haven't tried it at any faster speeds yet. It will come on and stay on when you are decelerating or coasting. If you have a heavy head wind it will not come on to often.

 

i am replying to Loos230about what he said on the first page about putting in a switch to determine either 4 or 8 cylinders i have an idea but idk if it would work or not and that would be to find an adapter to insert into your selected injector and you can flip a switch and it will completeor disrupt the circuit so there would be no gas in the chamber and thus not have a working cylinder and i know it would throw a dtc but idk if the computer would compinsate and dump more gas down the working injectors but when u wanted to go back to 8 you could and you could buy a little computer thing to clear the codes

anybody know if this idea would work

 

I saw that post on another forum. I'm actually gonna try the install myself. Went out and bought the LED and stuff today... Only differance is that i'm going to put in a cut out for the light but from where i'm thinking on putting it, i don;t think it will affect me. I'll let yall know how it goes. gonna put it in 1 of 3 places.. that little useless cover where the one in the post is, just infront of the spedometer, or on the left hand side of the dash. leaning more towards the useless cover..

 

nah, your truck would act like it had a miss and you would lose power. The valves are still working so the piston would still be compressing the air....just not air and fuel.

 

I think you'd actually lose power and maybe ever worse mpg if you cut off injectors because the valves would still open and close causing the cylinder to fill up with pressure which would slow the piston down as it approaches TopDeadCenter