Yikes. Be careful about not running the vehicle very long by just the alternator, it can damage the computers.

Have you looked at the IPDM?

 

I bet you have a stuck relay.

 

But which relay?

 

The one you just installed.

 

Where did you get the replacement Relay from? I ask, to be certain it is the correct Relay, not something that is simply "close". Quite unusula in my experience to have a brand new Relay be stuck. Where there any problems before hand?

Dealers sell the ECU Relay for about $3.50. It is different than all the others, albeit in a minor way.

 

From his post in the other thread, he stated he swap with the fog lights relay.
I would do as TitanBlue say, go get some correct relay and go from there. There's been situation that the whole IPDM needed replacing.

Sent from my Titan.

 

I first tried the fog relay and it cranked up fine but would not shut off. So, I went to the local dealer and got the correct relay and again it cranks up and runs fine but will not shut off. Dealer wants $442 for the IDPM which I could put on but I have read all the posts on this subject on here I believe and this has never been mentioned as a side effect of changing the relay. I was hoping someone has a little more insight into what could be the cause of not shutting off. I have never owned a vehicle that would not shutoff with the key removed so I am at a loss right now.

 

I have never owned a vehicle that would not shutoff with the key removed so I am at a loss right now.

I have never had this either. Trying to help brain it out as an armchair mechanic.

For some reason, it is getting power to the fuel and ignition when it should not.

If you pull the new relay, it should die. If it doesn't, it must have a short between that relay and the fuel/ignition circuits.
I bet if you kill the motor and leave the battery hooked up the battery will die.

 

Yes, when I pull the new relay it stops emediately. I have not tried pulling any of the fuses yet.

 

Next move is to look for some wires melted together ahead of that relay. Removing the relay cuts the fuel supply.
That relay is staying powered up when it should not.
Testing for 12 volts at the coil pack won't help. We know it has spark. Spark and fuel should shut of together.

Where is the truck? City and state?
Year and miles on truck? Could be as simple as a stuck ignition switch on the back side of the lock cylinder. How many keys are on your ring?

 

How much and how long did you crank the crap out of it trying to get it to start when it first would not start?
Excessive cranking could have possibly melted a couple wires together somewhere.

 

Yeah i remember a thread where a harness was crushed and wires shorted together.
That member couldn't shut the truck down either.
A few others had their problems trace to faulty remote starter module.
One had water inside his truck and had the same problems.

Sent from my Titan.

 

Well I just drove the truck to see if everything works and it does. However I did notice that the warning light with the key in the center of it is on. I did find out that I can also pull what I think is the ignition fuse and it stops running and the condenser fan comes on and goes off when you put the fuse back in. I know the warning symbol has to do with the imobilizer system but don't know what fuse controls it. There is also a slight buzzing sound coming from somewhere unless you take the negative terminal off the battery.

 

The ignition circuit, which also powers up the fuel relay is staying hot.

The condenser fan is probably temp controlled so we might ignore that for now or turn off the A/C.

Just for giggles, unplug the condensor fan and see if the truck still does it. Look at the plug for damage. I know there was a recall for condensor fan wiring on some trucks. The fan does initially power up with the A/C, which is on the switched ignition power. If something went wrong with the fan it could possibly be back feeding to the ignition/fuel circuits.

 

OK , does anyone know which fuse controls the NVIS system . I believe the problem may be related to this since the light does not flash but just stays on all the time.

 

Try a different set of keys

If you were local id help you disable it with Uprev

 

I have traced the high pitched buzzing noise to inside the transmission, and that is with no engine running. Maybe a solenoid or something? I put my ear against the pan and it seemed fairly loud. After pulling the outer ignition fuse the NVIS light has now gone off. I may have to break down and take it to the dealer tommorrow.

 

I suspect the melted wiring harness theory.

 

I have looked at what I can see of the harness and it does not look damaged on the outside but who knows?

 

Well, the mystery is solved. A while back my son had a large rear seat speaker wired up and the wire was shorted on the frame somewhere. When the wire was disconnected the problem was gone. I only had to pay for the diagnostic fee and a few bucks more.

 

That's good to hear. Must be powerful speakers to power the V8.

Sent from my Titan.

 

Yeah, something my son had hooked up at a audio shop. I never would have thought of looking for a problem there.