david1993

Hi guys have a problem with my 97 f150 with a 4.6 driving to work this morning my radio cut out then realized my Windows wouldnt work and my dash lights went out. Voltage guage went down to the bottom rest of guages were okay also had abs light going on and off. After about 20 mins everything started working again. But voltage guage was fluctuating. I have subwoofers as i turn it up to see if guage would move it did. Never had a battery light come on. Going to work on it after work today

Jbrew

Sounds like a battery problem. Could have allot corrosion, look under the truck at the starter connections. They like to corrode there. Be carefull with the small wire, -takes a 10mm to remove and clean, but those like to break, -the stud itself does. Some of them are double nutted. Make sure you two wrenches on it if that's the case, -so it doesn't break.

david1993

Thanks for the input will be sure to check those things

david1993

After work pulled it in the shop had it running read voltage was at 9 volts running. Shut it off and wouldnt start no more. So replaced alternator had running voltage between 13.5 and 14 volts. Drove home 14 miles with no issues

Jbrew

Yea, they won't start below 11.4 volts.

A good alt will show over 14 volts maintaining charge. 14.6 or 14.8. When you test the alternator, use absolute ground or close to it. That would be the alt case. Absolute is where it bolts to the engine block.

A good battery will settle at 12.3 - 12.6 about an hour after shutdown.

Glad you got her fixed!