Help! '03 Expy - Battery or Alter. Problem?
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Cross-Country
Joined: Feb 2005
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Help! '03 Expy - Battery or Alter. Problem?
Help!
My wife's 03 Expy died on the way home this evening. ABS light came on and then lights dimmed and quit running.
I had this same problem about 8 months ago, and replaced both the battery and the alternator. This fixed the problem, although the alternator light stayed on. I took it to Ford and they diagnosed a bad wire on the wiring harness that goes to the alternator. It was still charging the battery, but the signal wire that goes to the computer was not sensing the charge. So it ran fine, but the alternator light stayed on.
Of course it was one of those things I kept putting off to fix.
So my question is, how can you tell if it's the battery or alternator? The old trick would be to jump start the car and then take off the positive battery cable. If it died, the alternator was bad.
Not sure if this works w/ newer cars or if it might damage the computer.
Any help greatly appreciated, as I'll have to stay home from work tommorow and fix it.
Thanks,
John
My wife's 03 Expy died on the way home this evening. ABS light came on and then lights dimmed and quit running.
I had this same problem about 8 months ago, and replaced both the battery and the alternator. This fixed the problem, although the alternator light stayed on. I took it to Ford and they diagnosed a bad wire on the wiring harness that goes to the alternator. It was still charging the battery, but the signal wire that goes to the computer was not sensing the charge. So it ran fine, but the alternator light stayed on.
Of course it was one of those things I kept putting off to fix.
So my question is, how can you tell if it's the battery or alternator? The old trick would be to jump start the car and then take off the positive battery cable. If it died, the alternator was bad.
Not sure if this works w/ newer cars or if it might damage the computer.
Any help greatly appreciated, as I'll have to stay home from work tommorow and fix it.
Thanks,
John
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Joined: Jun 2004
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get yourself a volt meter... like $12 a autozone.... put it on the battery when car is off... should be returning 12 volts... if its like 11.8 - 12.2 area, battery is fine.
now start the car... put the volt meter on battery while car is running... (with lights, radio, and AC off)... should be returning somewhere in neighborhood of 13 - 14 volts... if its lower your alt is going bad. Now try it with AC, lights, and radio on... it will be a bit lower, but shouldnt be much lower... if its ever returning less than 12.8 volts with the car running... get urself a new alt.
Optima red top battery and a motorcraft rebuilt alt is the way to go... installing a new alt and battery if necessary literally takes 20 mins... if you have any mech ability at all, dont pay ford to do that job, its a 2 on the 1-10 scale...
I keep a volt meter in my Expi and my Cobra... and check them regularly... as long as i see over 13 volts with motor running, all is fine.
now start the car... put the volt meter on battery while car is running... (with lights, radio, and AC off)... should be returning somewhere in neighborhood of 13 - 14 volts... if its lower your alt is going bad. Now try it with AC, lights, and radio on... it will be a bit lower, but shouldnt be much lower... if its ever returning less than 12.8 volts with the car running... get urself a new alt.
Optima red top battery and a motorcraft rebuilt alt is the way to go... installing a new alt and battery if necessary literally takes 20 mins... if you have any mech ability at all, dont pay ford to do that job, its a 2 on the 1-10 scale...
I keep a volt meter in my Expi and my Cobra... and check them regularly... as long as i see over 13 volts with motor running, all is fine.
Logistics Pro
Joined: Jul 2003
Posts: 3,595
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From: Lawton, Oklahoma
There was a problem with the alternator wiring looms on some of the later model Expeditions. If they recommended replacing it then you are beating a dead horse until you do that. A new alternator will not fix it. If I paid someone to put on an alternator and the light was still on when you picked it up, they would be fixing it right for free.
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Cross-Country
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Thanks for all the replies, just wanted to follow up on the repairs. I jump started the car and with the engine idling only measured ~10V at the battery, which would seem to mean a bad alternator. I pulled the alternator and took it back to NAPA as it was only about 6 months old. They replaced it for free. While I was gone, I put the battery on charge. When I returned after a couple hours, the battery didn't seem to be taking a charge so I took it to Walmart and they replaced it for free as it was only 18 months old.
I also ordered a new alternator wiring harness, and replaced that today. With the engine idling I get 14.0 V at the battery, so I think everything is fixed and the bat light is no longer lit up. I was glad that I had the forethought to put the receipts for the battery and the alt in the glove box, so the only cost of the reapir was the $39 wiring harness and a day of vacation.
Thanks for all the help,
John
I also ordered a new alternator wiring harness, and replaced that today. With the engine idling I get 14.0 V at the battery, so I think everything is fixed and the bat light is no longer lit up. I was glad that I had the forethought to put the receipts for the battery and the alt in the glove box, so the only cost of the reapir was the $39 wiring harness and a day of vacation.
Thanks for all the help,
John
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Joined: Jan 2001
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From: Central NYS
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Joined: Dec 2005
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From: Billings, Montana
Having both go out along with the bad harness doesn't suprise me, I've seen stranger things happen. It's a shame that the products you buy these days don't last, but at least they replaced them for you. I too hang on to my receipts for this reason. I'm glad you got it fixed. Thank's for the follow up.
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