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

77,935

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.

4,565

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.

4,565

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 226,796 nationwide F-150 listings starting at $1,250.

ZIP:

Ford F-150 Experts

  • #1
    OJ
    Reputation
    9,730
  • #2
    dandyoun
    Reputation
    4,660
  • #3
    tennisshoes
    Reputation
    3,370
View All

Related Models For Sale

Used Chevrolet Silverado 1500
3,078 Great Deals out of 163,285 listings starting at $1,500
Used GMC Sierra 1500
1,306 Great Deals out of 63,547 listings starting at $1,200
Used Ford F-250 Super Duty
489 Great Deals out of 47,257 listings starting at $1,817
Used Toyota Tundra
714 Great Deals out of 34,859 listings starting at $1,995
Used Dodge Ram 1500
380 Great Deals out of 11,061 listings starting at $1,699
Used Toyota Tacoma
673 Great Deals out of 41,737 listings starting at $2,500
Used Ford Mustang
460 Great Deals out of 42,893 listings starting at $1,488
Used Ford F-350 Super Duty
395 Great Deals out of 26,342 listings starting at $3,900
Used Chevrolet Tahoe
934 Great Deals out of 39,821 listings starting at $2,000
Used Nissan Titan
315 Great Deals out of 19,712 listings starting at $3,298
Used Chevrolet Colorado
379 Great Deals out of 39,040 listings starting at $2,290
Used Ford Explorer
1,232 Great Deals out of 65,108 listings starting at $1,499
Used Chevrolet Silverado 2500HD
450 Great Deals out of 29,883 listings starting at $2,000

Used Cars For Sale

2018 Ford F-150 Lariat SuperCrew 4WD For Sale
9,450 listings starting at $36,399
2017 Ford F-150 Lariat SuperCrew 4WD For Sale
27 Great Deals out of 1,929 listings starting at $30,500
2016 Ford F-150 Lariat SuperCrew 4WD For Sale
16 Great Deals out of 928 listings starting at $28,000
2015 Ford F-150 Lariat SuperCrew 4WD For Sale
52 Great Deals out of 1,498 listings starting at $23,988
2014 Ford F-150 Lariat SuperCrew 4WD For Sale
60 Great Deals out of 1,071 listings starting at $14,950

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.