Charging problems

[jamie deschamps]

Have charging problems with my 6.5 turdo. New alternator and still wont charge but rpm works but no charge to batteries

[N9Phil]

The first thing that I would do is to do a load test on your batteries. Harbor Freight has load testers that work great and don't break the budget. These load testers will also tell if you are getting the proper voltage out of your alternator. There is only a short wire from the alternator to the battery so it should be fairly easy to diagnose. There is always the posibilty that there is a short or heavy load causing the problem. (bad batteries can cause this).

http://www.harborfreight.com/catalogsearch/result?q=battery+load+tester

[trbankii]

Yep. Check the whole charging system - batteries, alternator, and battery cables. As Phil says, bad batteries can be a culprit. Also, a new alternator isn’t necessarily a good one. Finally, searching around here will show you how often the cables can be an issue. Corroded connections and deteriorated wiring can multiply issues.

[Robyn]

What year truck ???

Battery cables are the biggest cause when the alternator is good.

Check the voltage at the + lug on the alternator using a volt meter.
Ground the meter - cable to the frame of the alternator.

My bet is you will see plenty of voltage.

Cables cables cables

The side terminal cables corrode deep inside where you can't see it.

The alternator connects to one battery + cable and then via the cross over gets the second battery.

Even the ground cables at the block can corrode inside and fail.