Battery Light

5

Asked by Mar 07, 2017 at 08:36 PM about the 2008 Ford F-150 Lariat SuperCrew 4WD

Question type: Maintenance & Repair

I have a 2008 Ford F150 that will not start because of a bad ground on the starter relay. Needless to say, I still need to drive around so I've been starting the truck by applying voltage directly to the starter from the battery. The truck starts and runs fine but recently the battery light came on while I was driving. It stays on for about 30 seconds and then goes away. Why would the battery light come on? Bad battery/alternator?...

I tested the truck today and the battery seemed low with about 12.15V before starting but the truck started right up (battery is less than a year old). The voltage went up over 13V and stayed over 14V for the next 10-15 minutes. I had the hi-beam headlights on, the a/c and the radio. I could tell the alternator was charging the battery and just before 10 minutes in the battery light came on but there was no change in the voltage reading. It was still 14.2-14.4V but I DID hear a change in the noise. It sounded like the engine slowed down or got quieter momentarily before the light came on. My question is why would the battery light come on? If my battery and alternator are good what other possibilities could this be? Why would the light come on if the battery is reading 14.2-14.4V?

4 Answers

73,125

It may be that the battery is low. Try charging the battery back up to the full charge of 12.7 DCV, 12.5 DCV at least. Also look at the condition of the serpentine belt. It may need to be changed along with a new belt tensioner. Belt may be slipping due to the call of the amount of charge the battery needs.

1,915

the starter relay is the solenoid , thats what you're heating up when you jump it from the batt. The ground for that "starter switch" is the starter bolted to the motor block .there may be some kind of short down stream from the batt. because you had good voltage there but the batt light came on , thats what I'm thinking .12.5 volts is good for a batt. at ease , let us know what happens .

5

The PCM was bad.

1,915

Cool , if you took it to a garage they might have toyed around and still not found the problem , and of course they would have charged you , Thats why we work on our own .

Your Answer

F-150

Looking for a Used F-150 in your area?

CarGurus has 9,123 nationwide F-150 listings starting at $3,000.

Postal Code:

Ford F-150 Experts

  • #1
    OJ
    Reputation
    8,760
  • #2
    dandyoun
    Reputation
    4,480
  • #3
    tennisshoes
    Reputation
    3,010
View All

Related Models For Sale

Used Chevrolet Silverado 1500
185 Great Deals out of 10,634 listings starting at $2,500
Used GMC Sierra 1500
235 Great Deals out of 10,481 listings starting at $2,995
Used Dodge Ram 1500
52 Great Deals out of 530 listings starting at $2,995
Used Ford F-250 Super Duty
19 Great Deals out of 779 listings starting at $3,000
Used Toyota Tundra
24 Great Deals out of 784 listings starting at $3,999
Used Toyota Tacoma
34 Great Deals out of 795 listings starting at $5,995
Used Ford Mustang
7 Great Deals out of 1,190 listings starting at $3,500
Used Nissan Titan
24 Great Deals out of 667 listings starting at $710
Used Chevrolet Colorado
16 Great Deals out of 1,301 listings starting at $1,999
Used Chevrolet Tahoe
5 Great Deals out of 645 listings starting at $6,871
Used Ford Explorer
42 Great Deals out of 1,369 listings starting at $3,900
Used Ford F-350 Super Duty
31 Great Deals out of 1,065 listings starting at $7,499
Used Chevrolet Silverado 2500HD
11 Great Deals out of 813 listings starting at $5,995

Used Cars For Sale

2018 Ford F-150 Lariat SuperCrew 4WD For Sale
18 listings starting at $56,530
2017 Ford F-150 Lariat SuperCrew 4WD For Sale
912 listings starting at $46,558
2016 Ford F-150 Lariat SuperCrew 4WD For Sale
5 Great Deals out of 63 listings starting at $37,600
2015 Ford F-150 Lariat SuperCrew 4WD For Sale
5 Great Deals out of 78 listings starting at $35,988
2014 Ford F-150 Lariat SuperCrew 4WD For Sale
28 listings starting at $19,995

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.