2000 Ford Excursion 7.3 rwd

For the past year or so my truck will develop a no start condition. I'll put the key in run and wait for the WTS light goes off then turn the key to start it. Nothing happens it just clicks as if the batteries suddenly died. Usually too remedy this I would disconnect the passenger side (ps) battery for a couple minutes then reconnect, it would would start and drive normally. This was a very random event and I could never predict or reproduce it. Sometimes when this would happen the "battery saver" relay in the under-dash fuse box would click repeatedly.

Fast forward to two weeks ago. I get back from the Air Warfare Symposium and it happens again. I get it started and drive to work. During lunch she starts up and drives fine. 1 hour later I ho to an appointment and the issue happens again. This time I get her started and then drive about 100 feet and then stalls. After a couple of attempts I get her to start again and everything is fine. Time to ho home and another no start issue. I get it to my gf house and haven't been able to get her to start ever since.

I've had the batteries tested (they're only 1 year old) and they're perfectly fine. The alternator is only a year old as well. I do think I should replace the battery cables but I can't find the motorcraft anymore.

Any advice? I'm stumped and electrical diagnostics is not my strong point at all.

Here's a video of me trying to start her:

 

In this video it almost starts but doesn't then you can hear the relay clicking

 

In this video the key is in the ignition, the door is open, and you can hear the relay clicking as well as the chime happening wherever it wants to. Also, if I press the brakes during this, it all stops.

 

In this video its just being wonky. Neighbors Chevy starts right up in the background lol

 

I had this problem and I was able to remedy it by turning the key to the run position. Then use the buttons on the key fob to lock and unlock the truck. I don't remember exactly which one fixed it but the clicking will stop and you can start the truck. I hope this helps.

 

Is your ignition broken? If the PATS is getting mixed signals it can create similar conditions. My ignition had a broken piece inside that caused me a lot of problems. Load up ForScan or similar Diagnostic reader and check your PATS system for codes. Mine was saying the PATS system antennae was not getting a signal, so the key chip was not communicating with the module in the column.

 

I had a similar issue. I ended up taking it to the dealer and they found a broken wire in one of the harnesses.

 

spit balling here. but could it be the starter relay that is in the engine bay fender wall? been a while since I had my 7.3,
there were times I just arked the posts with a screw driver to get home before I could replace it.

 

Ive tried this and nothing

 

Only scanner I have is the bluetooth OBDLink

 

Thats a lot of wiring to go through. I hope it isn't something as hard to troubleshoot as that.

 

Where's a good source to buy battery cables for these things?

 

Will it give you any codes? DTC'S for the PATS system by chance? ForScan is free. If you have two keys try the other one to see if that changes anything. You have to try to eliminate each system as the cause of your issues.

 

Only DTC's were for glowplug circuit 2-4-6-8. No PATS system or anything.

 

Good news is....I got Rasputia started.

Everytime I went to start her she'd cut all power and the car wouldn't do anything with the key in any position. I would disconnect the positive cable for the passenger battery for 5mins, then I'll have power back until I tried to stay the engine and continue the cycle.

I noticed that everytime I reconnected the battery cable and leave the key in RUN position for a longer period of time than the last attempt, she'd get closer to starting. So on my last try I reconnected the battery cable after a failed attempt. But this time, I left the key in the RUN position for 15 mins. After 15mins she started up with the fury of a straight-line 7.3 that hasn't started in weeks lol.

Weird thing....my power windows and locks no longer work anymore.

I did the GEM test with FORScan Lite on my phone and these are the results: