vincemacpaul

2000 XLT 5.4L Gas
Hi.
4 year old battery crapped out during a night deep freeze (23d here in southern Mississippi). Hooked up charger without disconnection from system. Wrong I understand now. Nothing happened for the next 6 hours. Charger is good as I charged another one after that. Bought a new battery and installed. Car parts guy said it was a few amps higher than OEM. Lights, windows, flashers.......all work fine. Engine cranks great and strong, but no fire. It has always cranked immediately. I suspect I fried a component or the computer needs to be reset. I've changed out the batt a few times in the past with no issues. Don't know where to start. Please advise. Thanks.

SCORGE

Are terminals and leads clean?

techrep

iTrader: (1)

He stated if cranks fine, just won't start... I would check all fuses.. what is the PATS light on the dash doing ?

SCORGE

10/4

BadFish523

Moved to the 97-03 section, you'll get better response here. I also agree on pulling all the fuses and checking them, also agree with checking the status of your PATS light. Check these things and get back to us.

vincemacpaul

Re-connected neg batt terminal. Again. all electrical systems are functioning great with strong crank. Idiot lights........I've never seen this, but right side, 3 o'clock, rectangular battery icon is on. It stays on as long as the batt is connected regardless of key position and whether the key is in or out. PATS light intermittent on and off. Sometimes fast/slow, but always flashing including when trying to start. I had a spare key made 10 years ago that worked at last use 5 years ago. It's in another State and will be here in 2 days. I think that will be the first thing to check before anything else. Will update. Thanks for the info.

R&TBabich

There is nothing "wrong" with connecting a battery charger without disconnecting the battery.
Once an engine is running the alternator is a battery charger.
If one of my vehicles is not going to be run for a month or so I hook up a battery charger.
What is the voltage with the battery connected?
Check, I think, fuse #11 - alternator field.
The battery icon is really an alternator warning light indicating the computer has detected an issue with the charging system.
You can drive with the battery icon lit until the battery dies.

vincemacpaul

That all makes sense. It shouldn't make a difference whether the batt is being charged by the alternator or an outside source. That just popped in my head when the issue started.
I just hook up the charger once a month to the cycle and lawn tractor during the off season till it shuts off.
Voltage at batt disconnected=13.125v
Voltage at batt connected is only a barely noticeable drop and the only draw I see is the hood compartment bulb (analog multimeter).
Fuse #15. It took me 5 mins to find the fuse box, haha. They're not numbered. I'll see if I can find a diagram somewhere online or possibly this forum.
Intermittent indications........ When I just tested for voltage as suggested, I tried to start again. The batt icon is not on as it was last time and the "theft" light goes off after (+-) 3 seconds while during a 10 second crank. Speed and tach needles jump up and down and the idiot lights flash at start up, but I've never really noticed what's normal so I can't compare.
Working spare key will be here this weekend so that's my best hope for a solution. But please bear with me and continue to share your knowledge. I find the odds astronomical that after 17 years of working it would crap out at the exact same time the battery died. But the facts are as the facts are. Merry Christmas folks.
Thanks for all's help. Please bear with me.

kd4gij

You can download the manual for your truck from the link below in my sig.

jethat

I had a crown vic awhile back and the battery died on it got a new one and it did simular stuff. Ended up the alternator was fried to. Dont know if thats your deal but you might try pulling the alternator off and have it tested..