1992 ford f150 4x4 installed new battery cable ends, new battery, new alternator. My amp gauge is showing slight discharge(equivelant to a quarter tank of gas), even after replacing these parts, lights are bright and truck runs great, can anyone shed some light on this, can the gauge itself be bad?...it is the original.I have not had a dead battery yet, so I can't tell if it is actually charging

 

well im no expert but i would say it sounds like the gauge..

i would say check the belt tension and make sure the alternator is working the way its supposed to..

also u can always purchase a cheap volt meter off of ebay just to check to make sure what your readings are..?

 

Its a new alternator, but I guess it could be weak, I have a voltmeter that I will check it with when it stops raining and the serpentine belt is pretty tight, but than again, I get up almost every morning and start the truck and have to check the belt, because 9 times out of 10 itslips halfway off pully on the smog pump, so maybe the belt is bad, but would that cause a low amp reading, even if the belt is tight??

 

well this is just a long shot but if the belt is bad and is coming off the smog pully then it maybe can not be spinning the alternator enough to fully charge the battery

 

I would look for the reason that the belt is jumping off, first. Either an idler pulley or tension pulley out of alignment. Then set the belt tension. With a meter, check voltage with the engine off, then with the engine running. The off voltage should be 12-12.5 volts, engine running should be 13-13.8 volts. That would tell you the altenator is charging. I would tell you how to full field the altenator, but if you have never done it, not adviseable.