Battery discharging

[bean]

My battery appears to be discharging a little at a time. How do I track down the culprit? I replaced all the ground straps couple months ago not sure how long this has been going on. I disconnected the radio just to see if that was it but No luck. Any direction is appreciated.i should also say within past month I replaced the regulator when I put volt meter on it charging was less than 13. Help!

[Willys_MB]

I recently had to deal with a cheap Chinese relay hat had failed on me. Not sure if you have HEI or any other relays, but that’s one place to start.

It also sounds like your voltage regulator might have a problem. What output does your alternator have? Is the regulator dropping it below 13V? I went to an internally regulated alternator and never looked back.

[bean]

I just replaced the regulator and it's charging at 13.6 now. I do have he I. Where exactly is this relay?

[sick472]

Disconnect the neg wire ground wire from the battery, then use a multimeter to check the amp draw between the neg post on the battery and the ground wire you just unhooked. Between 20 and 50 milliamps is pretty normal...more than that is suspect. Start pulling fuses one at a time and look for the fuse that drops the amp draw down significantly. That will be the suspect circuit.

Keep in mind that the dome light door switches will activate when you open the door and change your readings. Wedge something in there to keep the dome light from coming on. AND, make sure your multimeter is set correctly and that it can handle 20 amps.

If none of the pulled fuses show the drop in amps (don't forget the 2 fuses under the hood)...your circuit is likely under the hood somewhere or at least outside the fused circuits.

[Stocker]

You can do pretty much the same thing with a simple 12v test lamp. Pop fuses one at a time and check each circuit. If the test lamp lights up on a particular fuse position, there's your culprit.

[Andy4639]

Originally Posted by bean

I just replaced the regulator and it's charging at 13.6 now. I do have he I. Where exactly is this relay?

Is this at idle are driving? Is it with AC on radio heater what?
13.6 isn't enough juice at the begining if it starts dropping once you start turning on stuff.
If it's 13.6 @ idle and nothing on try turning on several things like lights heater/AC and see what it's doing. Could be a bad alternator and not putting enough charge back to the battery.

[bean]

This was at idle. Would a loose connection on the alternator cause this ? I was at work and in a hurry but did find a loose terminal on back of alternator so got that tightened. I 'll check those things you mentioned and will get out the multimeter tonight when I get home. When I first replaced regulator it was charging at over 14. What should it be at idle?

[truckster]

Originally Posted by bean

I just replaced the regulator and it's charging at 13.6 now. I do have he I. Where exactly is this relay?

You don't necessarily have a relay for HEI, only if you installed one.

[Andy4639]

Originally Posted by bean

This was at idle. Would a loose connection on the alternator cause this ? I was at work and in a hurry but did find a loose terminal on back of alternator so got that tightened. I 'll check those things you mentioned and will get out the multimeter tonight when I get home. When I first replaced regulator it was charging at over 14. What should it be at idle?

Yes any loose connection generates heat. Which is a lose of power to wherever it's going. With the truck at about 2000 RPM and just about everything turned on you should be getting at least 14 volts are a little better.

[rharris]

Not to insult intelligence but make sure DMM is on DC Amps (it's sometimes overlooked). It will read on AC amps but will jump around and give erroneous readings. Good luck