Help Needed Batteries? Alternator? Or Short?????

[easyrider1234]

I have a pretty stock 03 f350 with a 6.0. Been having an electrical issue for the past week. My electrical system has been really weak. I obviously noticed it mostly at night running the lights, they are really dim and seem to brighten when the engine revs. Alternator right??? When I turn the engine off and try to restart it. Its dead. I have been charging the batteries overnight and it does let me start in the mornings but I cant turn off the engine because it wont start again. I havent taken the batts and Alt off and ran the auto parts store to have them checked. I did stop by checker auto and while the engine was running the voltage fluctuated between 8-11 volts. Not a constant 14.5 give or take. Is there a regulator or something I can check here at home?? also I noticed the batteries were bought 8/08.HELP

 

[rammertide07]

Have you tried replacing the alternator? Thats where I'd start, even though it would cost me....I would start elleminating possible problems judging by what it is doing. I believe even if it was the batteries you would still be picking up a higher voltage rating coming from the alternator. And the fact that you can charge the batteries and it will start (so it they will take a charge). It just takes so much energy to start a diesel first off and then to run the electrical systems....the alternator just can't keep up.

 

[easyrider1234]

Thanks!!! I just needed to confirm what I was thinking. I did stop on the way home and picked up an alternator. Just in case. We live about 30 min from town and got about three feet of snow the other day. I think I will give the batteries a good charge overnight and put the new alternator on in the morning. Thanks again

 

[BIG JOE]

Thanks!!! I just needed to confirm what I was thinking. I did stop on the way home and picked up an alternator. Just in case. We live about 30 min from town and got about three feet of snow the other day. I think I will give the batteries a good charge overnight and put the new alternator on in the morning. Thanks again

Inspect and Clean yer battery cable connections, Real, Real good.

You might wana do that first.. then start it.. let it run fer 5 minutes, do a volt check.. then turn on the lights.. run the heater.. do another volt check'n see what you get.

Joe

The regulator is built into the Alt. Non repairable. (IIRC on a 6.0)

 

[easyrider1234]

Will do... They seem pretty clean, when I disconnected them to put on the charger they were on tight with good connection. But I will defintly run the test before I put the new alt. on. You guys have been a big help. Its good to have the help.

 

[ghoff]

if your batteries are not sealed, you can pull the caps off and check the water with a hydrometer. Sometimes one or more cells can go bad. You can also look at battery voltage with engine off. A fully charges Batt. will read about 12.68 v. Disconnect one battery from system to accurately read each Batt. individually.

Then, with engine running, check voltage. If it is charging you should see something between 13.5 - 14.5 v, depending on how many amps the Alt. is generating.

Also, check the terminal at the back of the alternator. Make sure it is clean and tight. I recently smoked mine due to a bad connection.

 

[easyrider1234]

Thanks, I will check em out.