Morpar-Lover here:
Long time reader first time poster.
I have a 2002.5 Dodge Ram 1500 quad cab.
It's got the 5.9 Magnum engine in it.

It's been a great truck for many years.
Today though something very odd is happening.
I thought i had a dead battery..temps dropped down to 40 here last night.
I took it to Advanced auto and it tested good. 12.8
I thought this was odd since the dash lights would not come one at all, other than the odometer.
When I put the key in the ignition I get the "hey stupid your keys are in the ignition and your drivers door is open" beeping. This is all normal.
When i turn the key is when it gets weird.
I have no other dash lights (air-bag, check engine etc..) and the odometer turns off. I don't hear the fuel pump or even the starter clicking. The motor doesn't turn over and the radio turns off. Then when I turn the key back to the off position and just leave it stuck in the ignition the odometer won't come back on?
This seemed to me like a bad ground or something or the battery was indeed dead. However when I moved the keys into AC mode I can roll the windows down at normal speed, lock/unlock the doors play the radio. it's like everything but the ignition is working.
Anyone have any ideas?

 

You have a good starting point. Check your grounds and your battrey may juat be dead enough to cause all the problems.

 

I forgot to mention that I just replaced the battery two months ago and I just got back from advanced where this new one tested good a few minutes ago. I think I have something wrong with the ecu or the fcm.

 

I have the same truck, it did the same thing. It was happened cause of the batt having too many dead cells...aka a ****ty batt.. Hopefully its nothing worse than that man.. swap in a fresh batt and see what happens. Or the ignition switch could be pooin out..

 

How would I test the ignition switch without buying a new one?

 

there is a big ol fat relay under the hood.. APS? something like that..

go over to the second gen board and post the same info- they'll fix you right up..

my guess is that the relay is a goner... question remains, if so, what made it pop?

 

To the OP here you go. This Guy knows his stuff check that out and see if you arent back on the road soon.

 

I looked into the relay and since there are two relays that are the same kind I switch them around and got the same thing.
I also noticed all the other relays were the same kind as well. So i just kind of started to switch things around.

I was testing each time i switched them.
It is doing something different now.
When I try to crank the truck the odometer goes dark and nothings happens.
No fuel pump priming or anything. No clicking from the starter.
But no i cna do it over and over and it doesn't slowly go dead like it was before.

Before this when i cranked it over and over it eventually just went totally dead.
Even though I could power the windows up and down just fine and lock/unlock the doors. The windows of course would go at the speed they normally do.

 

So I got another go at the issue today. I was trying to look at the bottom of the fuse block and suddenly I here my "yours keys are in the ignition" beeping go to the slow beeping of "crank the truck dummy." Then I moved it and suddenly it went back to just quick beeping. I thought that was weird so I pulled on it again and it went to slow beeping. I got in the truck and the dang thing cranked right up?
So I pulled the fuse block up and over towards the engine so i could remove all the connectors underneath. I cleaned them up with a rag and plugged them back in.
Then it cranks just fine!!!

 

Glad you got it all working!