Hi all, we have a 2001 F150 Super-Crew (5.4L, 2V, automatic trans, 2 wheel drive) truck that has been a very good vehicle for us. We have some kind of drain on the battery and I am trying to find it. I am recharging the battery right now and when it is done I intend to get my meter out and see if i can find the source of the drain. Anyway, for some reason, in the past whenever we have disconnected the battery (either to replace it or to do some work on the truck) we can count on the truck not starting due to the PATS system. Don't know if something is wired wrong or what, but I had to have the truck towed home from Costco a couple of times, after getting a new battery installed. Also in the past, after we have disconnected the battery to work on the truck, when we re-hook the battery up, it won't start. Just cranks. Over the years I have gotten different advice on the PATS system and the blinking theft light, even looked looked online for a PDF of the PATS system that could help (never found a good one). My son usually will have to come over and spend hours trying different methods he finds online to get the truck to start. He writes down what worked but says it is never the same method when he has to do it again

In any event, every video of doing a parasitic drain test involves taking the negative battery cable off and wiring a multi-meter (set to 10 amps) between the negative battery cable and the negative battery post. My fear is that in doing so, that once I am done with the test, that I will have the same trouble with the PATS system, preventing from starting the truck. I am wondering about hooking up a BATTERY SAVER device saver while I unhook the battery to wire in the multi meter, then unhook the BATTERY SAVER device while I search the fuses for the parasitic drain. Then, after I have found the source of the drain, I can re-use the BATTERY SAVER device again while I re-hook up the battery. Do you folks know if this will keep the PATS system happy? Are these BATTERY SAVERS a good idea? They have some that use a 9 volt battery, and they have some that plug into the OBD2 port - which do you guys think is best?

My wife and I are seniors on a very limited income so taking it to a mechanic ($$$) is not an option, especially here in California. However, although I may be slow and don't have the best eyesight, I usually find and fix what needs to be fixed.

Let me say in advance that I appreciate any and all advice so pour it on!

 

Normally disconnecting the battery has no effect on PATS because there is no power to it until the ignition switch is turned on for the self check.
It has no memory that would be lost from a lack of power.
Why not leave the ignition on long enough a minute or so for the PATS to flash a code indicating what the issue it then go from there to solve it.
It may not even be a PATS fault but a secondary effect. The PCM relay may be faulty not powering up the computer reliably..
If you get a two digit flash code, post it here.
The system was not designed to get around that easy.
.
If you have a drain, check the Alternator; engine OFF, first.. Remove the heavy power cable (safely) then retouch it back on the terminal noting if there is any spark.
If yes, the Diode stack is faulty or a faulty regulator has not turned the field winding off.
If found ok, you have more to look at. from other sources.
Good luck.

 

I agree the PATS system shouldn't have any problems when we disconnect the battery. But it does. Even a Ford service manager told me the PATS system can be finicky (he was the one who came to our house and took the negative cable off the battery. Then he told us to click unlock on the key FOB with-in 10 seconds of re-hooking the negative cable back on the battery. And this IS /ARE the key FOB's that came with the truck when it was new/off the lot. If i could I would permanently disable or remove the PATS system!

 

pops, I used to have a 2005 F-150 that I needed to check the parasitic drain on and I was able to do it without disconnecting the battery. I fashioned a jumper wire that had a large alligator clip at one end that would fit around the negative battery post. Then, I attached one lead from my multimeter, set on 10A, to a convenient screw at the negative battery cable near the post. Next, I loosened the negative cable so I could slide it up the post without removing it. The battery was still connected to the car at this point. Now, I slipped the large clip at the end of my jumper wire onto the exposed battery terminal. Finally, I connected the other terminal of the multimeter to the free end of the jumper wire. Now, I could slip the negative cable free of the terminal and the multimeter kept the circuit completed. Reconnecting was the reverse.

I did this so I could check for vampire draw and not trip the "high draw" in the circuit that exists when you first connect a disconnected battery. It showed me there was a constant, low Amp draw, about 0.05A as I recall that was keeping the PCM, radio and a couple other circuits alive.

However, I also replaced the battery in that truck without doing anything special to save any settings. The truck was without a battery for 3-4 hours. All I had to do, once the battery was reconnected, as I recall, was reset the clock and the radio. I also disconnected the battery for other purposes a couple times and at no time did I have any trouble with the PATS.

- Jack

 

Tell ya what!
You listen to the service manger and enjoy the problem until your ready to do the testing to get a lead.
That's why you wound up here.
You've been told the same thing on another board.
Good luck.

 

Hi all, wanted to give an update. Charged the battery again and got the truck to start. I was able to get a battery tester (the Ancel BA101) and after going through the testing sequence, it said the battery is good, but that the alternator is charging a little high?? I made sure their were no lights left on, or any other obvious current draw (radio, etc) and left the truck overnight. Came out the next day and tested the battery again. it still said the battery was still good, but that the charge level was down(around 70%). I was able to start the truck, and let it run for a while to bring the charge back to 100%. Anyway, it seems that I have some kind of draw on the battery. I know I will have to get the battery load tested somewhere, but my primary concern is the parasitic draw, AND the PATS/starting nightmare that happens when the battery is unhooked. If anyone has a good PATS system troubleshooting link that would be great.

Incidentally, I do want to say thanks again to all who offered help and advice. Even if we could afford a mechanic, I am not able to drive anymore, so I couldn't get it tested. My wife and i are seniors doing our best on a VERY tight budget so i try to do/fix as much as I can to keep things going without having to spend any money. I know there are some here who probably wonder why i don't do certain things or take certain steps. Well, I am disabled and can't walk without a cane, and my vision isn't the best, so it is hard for me to work on the truck. But i do truly appreciate and and all advice given, and I apologize for my repeated questions - i'm just trying to find a way to fix things under the circumstances we are in with the tools that I have

 

Load testing the battery will not accomplish anything.
What is a "little high" for charging?
Voltage varies with system charging a battery until the battery recovers it's charge, after a start. The regulator controls this action.
A simple check is with a volt meter to look at the charge performance will verify.
If the truck started, it's not the PATS system >>>>because it's not powered when the ignition is off<<<<<.
PATS is a start control system only, then is no longer active >after< starting has occurred.
I've tried to help you by providing solid information to work with but your not meeting it with common sense.
I'm sorry for your disability but there are NO short cuts to all this by guessing.
I wish you only the best out come.

 

Thanks Bluegrass! I probably don't do a good job describing our situation and i do apologize for that.

We've had the issue with the truck / PATS issue since the first time the battery was changed - that's when the Ford dealer service manager came to our house and said the PATS system is the problem and that it can sometimes be "Finicky". All we know is that whenever the battery is unhooked or removed/changed, getting the darn thing to start again is difficult. We have replaced the remote batteries, the remotes themselves, battery cables, truck ground, even the PATS chip keys over the years and still get the same results (crank/no start after changing disconnecting the battery). Sometimes the theft light is flashing/sometimes it isn't.

A few years ago, the truck got hit by another vehicle (their fault) and so our truck got to be repaired on the insurance company's dime. This was a 5 star mechanic shop (not just a body shop) with several mechanics. They had to remove the battery to do some of the repairs and when it came time to put the battery in and start the truck, they had them same trouble, crank/no start. After a day of screwing with the truck, they called us and we told them what we have told you. Their mechanic didn't believe us so he called a Ford dealer. Long story short, whatever they tried didn't work. 'Must be a problem with the "ECM' they finally told us. My son went over to the mechanics shop and after a couple hours of trying this and that, he got it to start.

Anyway, this all boils down to it being a major headache whenever the battery is unhooked. Now that we may have a parasitic drain, or perhaps an issue with the battery, or whatever else it may be, it looks like we may have to fully disconnect the battery to troubleshoot. That's why i asked if the "Battery Saver Devices" sold all over the place might hold the PATS settings. So far, I have heard some say "YES" and some say"NO". If the Battery Saver device does work, then this might allow us to disconnect the truck battery and once it is re-hooked /reinstalled, we wouldn't have to go through the PATS/starting trouble. I know to use the meter on the battery and the check for voltages, etc. What i am looking for is something to hold the PATS system alive when/while disconnecting the battery.

 

Pats work without the battery.

Do the work yyou are trying to do

What is the issue with your battery draw? If this is a vehicle that sits fir 6 months between starts, then there is your issue. Toss it on a battery tender.