99 f350 still drains batts alternator good
#1
99 f350 still drains batts alternator good
My batteries keep draining and my alternator is good could this possibly be an ignition switch? Please somenone help me out. I've replaced solenoid,starter and alternator?? Someone mentioned the ignition switch could this be the problem?? The only other new thing ive done is replace the terminals could it be a bad ground?
#2
Here is info. I saved on testing for drains. Hopefully, it will help you out.
This is the procedure I follow:
If no other electrical accessory are causing the battery to drain over night a manual draw check of the electrical system will need to be performed. What this means is you will be checking the electrical draw the battery has on it when the car is locked up, with the key in the "off" position". First open the hood and disable the under hood illumination light, if equipped. Next, with the key off and the doors locked wait 15 minutes, then disconnect the battery cable on the negative side. (The 15 minute wait allows the computers to go into "sleep mode" and shuts down all electrical). Attach a test light between the negative battery cable end and the negative battery terminal. The test light should illuminate dimly or not at all. If the test light is on brightly there is a strong electrical draw in the system. To locate this electrical draw start removing fuses one at a time. When the test light goes out the circuit in question has been located.
Note added:
when disconnecting the battery cables, the test light (or better, a good quality ammeter) should be installed across the first cable and the battery post, then the second battery disconnected. If you totally disconnect and reconnect, the GEM and other electronic modules "wake up" and draw more current. In normal "sleep mode" the total amp draw should be less than 50 milliamps.
A fairly common battery drain point is back thru the alternator if a diode goes bad. That usually kills the batteries in short order, but there may be a lower level leakage. Be sure to include disconnecting the alternator lead as one of the steps in finding the drain.
This is the procedure I follow:
If no other electrical accessory are causing the battery to drain over night a manual draw check of the electrical system will need to be performed. What this means is you will be checking the electrical draw the battery has on it when the car is locked up, with the key in the "off" position". First open the hood and disable the under hood illumination light, if equipped. Next, with the key off and the doors locked wait 15 minutes, then disconnect the battery cable on the negative side. (The 15 minute wait allows the computers to go into "sleep mode" and shuts down all electrical). Attach a test light between the negative battery cable end and the negative battery terminal. The test light should illuminate dimly or not at all. If the test light is on brightly there is a strong electrical draw in the system. To locate this electrical draw start removing fuses one at a time. When the test light goes out the circuit in question has been located.
Note added:
when disconnecting the battery cables, the test light (or better, a good quality ammeter) should be installed across the first cable and the battery post, then the second battery disconnected. If you totally disconnect and reconnect, the GEM and other electronic modules "wake up" and draw more current. In normal "sleep mode" the total amp draw should be less than 50 milliamps.
A fairly common battery drain point is back thru the alternator if a diode goes bad. That usually kills the batteries in short order, but there may be a lower level leakage. Be sure to include disconnecting the alternator lead as one of the steps in finding the drain.
#3
Your alternator "may" be the problem.
With the batteries recharged, let your truck sit overnite. In the morning when everything is cool, open the hood and touch your engine block and then your alternator. They should be the same cool temp. If your alternator is warm, then it is bad and draining the batteries.
With the batteries recharged, let your truck sit overnite. In the morning when everything is cool, open the hood and touch your engine block and then your alternator. They should be the same cool temp. If your alternator is warm, then it is bad and draining the batteries.
#5
Put a multi meter on the connects to see if there is a voltage drop when off.
And check all the battery terminal connections, one loose terminal can make a problem.
You need to check both of them too.
I added 4 extra ground wires to my system and it helped a lot.
Make good ground contacts, a wire brush on a drill wheel works good to clean up
the frame connections. Never enough grounds.
And check all the battery terminal connections, one loose terminal can make a problem.
You need to check both of them too.
I added 4 extra ground wires to my system and it helped a lot.
Make good ground contacts, a wire brush on a drill wheel works good to clean up
the frame connections. Never enough grounds.
#6
#7
if i benched tested the alternator would the diode show up as bad?
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#10
Try disconnecting one battery over night. If the unhooked bat stays charged rehook that one and unhook the other the following night. I've had one weak bat drain them both several times over the years. That has been my most common bat drain problem. I replace both bats if one is bad and use the other in one of my cars or tractors. Good luck.
#11
i have no idea if a bench test would identify a bad diode. The diode is on/in the alternator. The easiest way to test for the bad diode is to do the simple test I mentioned in my first reply to you.
#12
I really appreciate your help im gonna try your tips.thanks again.
#13
Put a multi meter on the connects to see if there is a voltage drop when off.
And check all the battery terminal connections, one loose terminal can make a problem.
You need to check both of them too.
I added 4 extra ground wires to my system and it helped a lot.
Make good ground contacts, a wire brush on a drill wheel works good to clean up
the frame connections. Never enough grounds.
And check all the battery terminal connections, one loose terminal can make a problem.
You need to check both of them too.
I added 4 extra ground wires to my system and it helped a lot.
Make good ground contacts, a wire brush on a drill wheel works good to clean up
the frame connections. Never enough grounds.
#14
Great info on here. I'm having the same problem with my 01 Ex. If I leave it alone for a day the batteries are dead. Going to try some of this advise to fix my problem. I tried new alt,new batts,cleaned grounds,batt terminals,and checked fuses. Hope I also can gain from this info. Thank you
#15
The bench test will not show you a bad diode. The hand held scanners will. The thing you gotta look for is on the bottom of the tag that prints out ( Midtronics ) tester does this. There will be a box with a squiggly line going from one side of the box to the other. If the ripples are tight and not really peaked out you are fine. If there is some high peaks and are far apart or really uneven climbs in that rippled line its a bad diode. That will only show you if they do a charging and starting system test.