How to test to see if you have a bad battery or bad alternator

Asked by Jun 29, 2015 at 11:11 PM about the 1997 Ford Crown Victoria 4 Dr LX Sedan

Question type: General

I started the car disconnected the battery
the car shut off within 20 seconds I believe
its the alternator I've taken the battery down
to the local auto parts store and they tested
it and they said It was good and within
range. But the battery was to low to run test
On the alternator so I have the battery On a
charger

2 Answers

105,275

First of all never ever disconnect a battery cable with the engine running, you can cause a voltage surge that can fry electronics. I had a customer that did that to his crown Vic and it wound up costing him 1500 bucks to get it running again. The proper way is to have a shop check the system on these high output charging systems, most of them are now computer controlled, so even thought the alternator checks good out of the vehicle it still may not work when in the car. You can check the battery the old school way by making sure it is fully charged, then just turn on the headlights with out the engine running for 20 minutes, if will crank over the engine the battery is strong enough to run your vehicle, if it don't crank it replace the battery. Or your local parts store can run a load test on it to see if it can handle full load or not. HTH

1 of 1 people found this helpful.

Thank u will try that . I'm charging the batter now

Your Answer

Ford Crown Victoria Experts

  • #1
    Tracy Hooks
    Reputation
    1,890
  • #2
    Tom Demyan
    Reputation
    1,110
  • #3
    tennisshoes
    Reputation
    800
View All

Related Models For Sale

Used Mercury Grand Marquis
29 Great Deals out of 1,701 listings starting at $800
Used Ford Taurus
232 Great Deals out of 14,953 listings starting at $1,800
Used Ford Mustang
602 Great Deals out of 38,610 listings starting at $1,895
Used Lincoln Town Car
35 Great Deals out of 1,737 listings starting at $1,099
Used Chevrolet Impala
572 Great Deals out of 34,336 listings starting at $890
Used Ford Explorer
1,181 Great Deals out of 68,925 listings starting at $750
Used Chevrolet Tahoe
786 Great Deals out of 41,559 listings starting at $1,987
Used Ford F-150
3,134 Great Deals out of 219,089 listings starting at $1,200
Used Chevrolet Caprice
146 listings starting at $9,995
Used Honda Accord
1,096 Great Deals out of 71,806 listings starting at $850
Used Chevrolet Camaro
438 Great Deals out of 31,254 listings starting at $1,450
Used Toyota Camry
1,035 Great Deals out of 85,966 listings starting at $1,296

Used Cars For Sale

2011 Ford Crown Victoria For Sale
122 listings starting at $4,250
2008 Ford Crown Victoria For Sale
110 listings starting at $4,500
2007 Ford Crown Victoria For Sale
74 listings starting at $4,510

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.