I have a security relay that replaces the PCM relay. You have to press the key FOB to contact the relay circuit in order to start the truck. I was in a hurry a couple weeks ago and the battery in my FOB was going out. I had to jump out and replace the security relay with the original relay to get the truck started. I got some new batteries for the FOB and decided I should put the security relay back in.

Just about the same time I did that my blower motor started working intermittently. I would go out in the morning to go to work and have no heater. In the afternoon when I would leave work the fan would come on again. It was getting frustrating but I didn't have time until this weekend to take a look at the problem. I checked fuses, all ok. I removed the blower motor and wired it directly to the battery. Blower motor worked fine. Now I'm getting mad because I am thinking I'm going to have to tear apart the dash to track down a wire. So I was back looking in my manual at the relays when I remember my wife saying, "how come the truck starts without pushing the button on the key FOB?" Then I noticed there is also a relay for the blower motor in addition to the fuse. I had put the security relay in the wrong slot. Instead of the PCM slot I placed it in the blower motor slot. So the truck would start weather you pushed the button or not, but the fan would only work if you pushed the button.

One of those stupid things, thought it was kind of funny. Glad I figured it out.

 

If I were you, I'd use that "special" relay in the IDM relay slot instead of the PCM slot.

It will do the same thing, disable your truck unless activated, but when the bad guys (who have already tweaked your door handle and jimmied your ignition cylinder) try to start the truck, everything will appear "normal" on the instrument panel to them. It'll crank, but it just won't start. If the instrument panel won't light up, they'll immediately know to start looking for something.

Since it looks to them just like the last SuperDuty they stole, they won't start looking for kill switches or "magic relays", and will just crank and crank.

Maybe the noise will arouse someone's suspicions, and they'll move on to one that WILL start.

Simple for you to move it.

Pop

 

Dude thats some funny stuff right there.

 

hmmmm Pop, that is exactly what it does. Dash looks normal, cranks over but won't start. I'm sure its in the PCM slot according to my relay chart. I'll check again though

 

Pay particular attention to whether you get a "Wait to Start" light or not.

Pop

 

where would you get a relay like this? Part number? How do you program the FOB to the relay?

 

I have the same 3 questions.