Ok, this is going to be a long history, but bear with me...

2005 Expedition Eddie Bauer, 5.4L V8 with 4x4 and after-market alarm, navigation/dvd head unit, amps, and speakers. I picked it up from a repo lot earlier this year, and all electronics were done by a previous owner.

About 8 months ago my wife and kids were visiting a friend and when they got ready to leave the truck wouldn't start. Wouldn't crank, wouldn't nothing. No starter ticking, no nothing. She turned the key and got jack. Called a tow truck since I was at work and couldn't leave, and before the guy loaded her up he tried once more to start it and was successful. She drove home, and since I didn't have time to deal with it that night, I put it off.

Over the intervening 8 months it's periodically required me to turn the key twice to get it to crank and start, but once it's actually engaged the starter it cranks instantly.

Three weeks ago the alternator and battery died, so I put new alternator and battery in it (probably not germane, but I thought I should mention it).

Yesterday morning when I was getting ready to leave for work it did the same thing to me that it had done to my wife... no matter how many times I turned the key, it wouldn't crank. I tried pulling the key in and out, tried shifting it to neutral and cranking from there, all with no luck.

So I sat in the truck, pulled out my iPad, and started to google what the problem could be. Got nowhere. I gave it one last try before calling my mechanic, and it started right up. I drove to work and it didn't give me another problem all day.

About 8:30 last night I heard a car alarm going off. We live in a big apartment complex in the middle of a huge city so I didn't think anything of it.

The alarm kept going on and off all night till it finally woke me around 2am and I looked out the window to try to figure out what a**hole was letting his car alarm go off all night. I realized it was me!

I grabbed my fob and silenced it through the window, lay back down, and within 2 minutes it was going off again. This time I got up, went outside, and checked to make sure I didn't have any smashed windows or anything, and silenced it again and went back in to bed. Within 5 minutes it was going off again. It was starting to occur to me that perhaps this was connected to the starting issues through a short in the ignition, and perhaps the alarm system thought someone was trying to hotwire the truck.

I went back out, silenced it, and this time I started it up, shifted gears a few times, shut it down, and went back in to bed and it never went off again last night.

This morning I get in my truck to go to work and the exact same thing as yesterday... turn the key a bunch of times and no luck. Again, I sat there for about 10 minutes without touching it, tried again, and it started right up.

I get to work, get parked, get into my office, and hadn't been in my chair two minutes when the alarm started going off.

One other possibly incidental issue, but maybe connected: the backup camera wired into the after market head unit works maybe 20% of the time. Sometimes it never registers that I'm in reverse, most of the time it does but won't activate the camera, and sometimes it actually comes on.

My first thought is that I have an ignition switch problem, and that explains not only the starting problems but also the car alarm issues of the past 12 hours.

However, I also know that the backup camera could be caused by a faulty shift selector switch, which could also cause the starting issues (though not likely the car alarm problems).

The last potential problem, and one that I'm fairly sure is not the problem, is the starter. The reason I'm saying I don't think it's the starter is because I don't hear the requisite clicking from the starter relay, so I'm thinking the crank signal is never making it beyond the ignition switch itself.

I have no play in the shift arm, and no play in the ignition switch itself. I pulled the rubber dust seal off the ignition and looked inside this morning, but saw no obvious issues. Unfortunately it appears that to dismantle the steering column and ignition assembly I need a star bit which I no longer have access to, so it looks like I'm going to be going to the mechanic.

Just hoping for some feedback to help narrow down and confirm my suspicions so I can avoid paying the mechanic his diagnostic time.

Any ideas?

 

I'd suspect that the remote alarm is disabling the starter interlock due to spurious inputs from the door/window latch switches. I would start with giving all five door latches and your window latch a "high colonic" with WD40 and see if you have a sticky door closed switch.

I'd also be inclined to eliminate the stater disable function of the aftermarket system for the interim, at least until you have a good handle on having solved the issue.

 

And how would one go about doing that? Honestly I could care less about the after market alarm and would be just as happy to remove it.

 

The starter disable relay (if external) or the internal function has to be bypassed and the original wiring restored.

Then have it removed. Any shop that installs alarm systems should have someone more than knowledgeable enough to do the opposite.

 

Ok, so I pulled the bottom dash cover and found the alarm control box. It's a Red Cobra 2907 which appears to me to be pretty cheap (Amazon for $30). I found the schematic on the back of the box and disconnected the wires for the siren and horn, and discovered that the starter interlock was already snipped. So that's not the source of my starting problems.

I also took the steering column apart and found no visible issues with the ignition.

So back to the source of my problem... Why is the key turning but not sending the signal to the starter to crank?

 

Did you verify that the interrupt relay was never installed?

 

How would I determine that? New to alarms...

The wire coming out of the alarm box for the interrupt is orange, and it was clipped about two inches off the box. However, I can't find any other end of that orange wire anywhere else around to see where it would have gone to. If you can direct me where the circuit is and how to check, I will definitely do so...

 

Unfortunately, there are at least four easy spots where an interrupt relay, if installed, might have been wired in according to the schematics.

 

I would focus some attention down on the DTR sensor located on the shift arm shaft of the tranny. This sensor is the neutral safety switch, the backup light switch, and the shifter position switch. All 3 of these circuits seem to in some way relate to the various issues you're having.