Hello all! We have a 2001 F150 Super-crew (5.4L, Automatic transmission, 2 wheel drive) which always has the same problem after we change the battery: No crank/no start/no nothing. Ever since we got the truck (new), whenever the battery was disconnected/replaced, the truck would NOT start (same symptoms: no crank-no start-no nothing!). A few days ago the battery went dead again (lots of clicking when we turned the key but wouldn't turn over) We charged the battery and it still wouldn't start, just louder clicking. (it was a VERY old battery but we hate to change them because of this issue). Last time this happened I had gotten 1 of those 9 volt battery memory savers, which we plugged in before removing the battery, and installed the new battery, and it started fine. Did that again this time but it didn't work. Just get the no crank/no start/no noise. But the instrument cluster does what its supposed to, and the radio presets are saved. - so I know the battery saver did at least save those. In past years we have thought it was a PATS issue because we sometimes had a flashing theft light. In those cases, my son scoured the internet, he found some steps to fix or reset the PATS system,, which he followed, and eventually got the truck to start (no he doesn't remember). So we need the truck so we changed the battery last night, with the 9 volt battery memory saver plugged in. After the install the truck won't start, but as I said the radio presets are there and the gauges on the instrument cluster move to their normal positions. **However, the "THEFT" light goes off as normal. But the truck won't start. So far I've clicked the unlock on the remote as normal, messed with the alarm/theft valet button, shifted the truck from park to neutral and back to park a few times, and it still have the same problem. I even found some instructions to reset the PATS system by putting the key in the door and turning it one way for 60 seconds and then the other way for 60 seconds - no luck! Anyway, I'm coming here hoping that someone here has had the same, or similar problem, and has a fix. As always, thanks in advance for all help, suggestions, and advice

 

Hooray!!! My son came over to help me. he went thru the connections and relays, while the key was being turned (Heard the fuel pump go on for a few seconds while listening at the fuel tank fill-up door, which was open & gas cap off). We didn't hear any clicking at the starter solenoid/relay on the firewall. So we then put the key in the #2 position and he shorted the 2 posts on the starter solenoid/relay on the firewall. - truck started!!! YEAH. Did it a couple of times to confirm. The truck still won't start with the key, but will by start by shorting the 2 posts on the starter solenoid/relay on the firewall. Does this confirm that the starter solenoid relay is bad? Or does something else come into play? I will gladly go get the part and have my son install it, I just don't want to change a part only to find I still have the same problem. Thoughts?

 

Thanks everybody. My son absolutely swears the problem is with the PATS system, and not a mechanical, fuse or relay problem. So I told my son that we were going to test the small wire coming from the ignition that lands on the starter solenoid, and if it was getting power, then we were going to go get another starter solenoid from the auto parts store. . .Before I could find my meter or test light my son, who has scoured the internet, asked me to do 1 test with him. He took me out to the truck, took off the negative battery cable, waited a short time, then told me to hit the lock & unlock buttons on the key fob 5 or 6 times each as soon as he reconnects the negative battery. I thought it was a waste of time but I did as he said. Guess what, the truck starts. Of course my son won't tell me where he found this tidbit of info, but it worked and the truck starts up & runs with NO problem. He said it was mentioned as a way to rest the PATS after changing a battery. So even though my truck is a 2001, and not a 2004 or later, it appears that the PATS system can in fact cause a no crank/no start condition for when power is removed for a certain period of time. I know that some 2004 Ford vehicles with PATS have this behavior, but I didn't think it was on my year.

 

while many say a 9 volt will help hold the pats memory ,as a master tech i have found that false in several cases, so now i use a 12 volt lawn tractor battery hooked to the battery cables with small jumpers, since doing so i have not had to have a single pats reprogramed . my own simple thought's are the lighter plug sometimes fails to back feed enough