Topic: Parasitic draw problems.

[QuestorThews]

I have been chasing down a draw on my battery for almost a month(weekend warrior) and I have finally isolated it to the voltage regulator, I think.  I did the normal parasitic draw test by pulling the fuses one by one to isolate one system, and when that didn't work, I assumed that it was the alternator.  But when I disconnected the alternator the problem didn't go away.  So I tried the voltage regulator.  When it is disconnected there is no draw on the system at all.  But I am hesitant to assume that a new regulator will fix my problem because I just replaced the regulator when I did the alternator a few months ago, so the one I have now should be good.  Do you fine folks have any suggestions or ideas that might lead me in the right direction?  I just want to be able to drive my truck! 

Oh btw, it's an 81 22r 4x4

Thanks!!!

[blackdiamond]

Sounds like you may have a "liberal" charging system...

Where did you get your alternator and regulator?  If you got them from a parts store with a lifetime warranty then it's not uncommon to have bad units. Just speculation, but maybe the regulators are a similar type item.

[Mudder]

Before pulling start the truck and check what voltage you're getting at the battery, with it running it should be between 13-14. As for the alternator and regulator being bad already, it is very likely if you bought it from a auto parts store. I'm on either my 4th or 5th one from O Reilly's. 

[84Flatbed]

How were you testing this, a voltage drop over a certain period of time?

[kneedownnate]

If you got them from a parts store with a lifetime warranty then it's not uncommon to have bad units.

Too true!  I went through several "lifetime" alternators, which killed at least 3 regulators, before getting back my money and buying a new alternator at a different parts house.  It has now worked trouble free for quite some time.

Also, when all this happened, the bad units fried some wiring in the sub-hanress that goes from the regulator to the alternator and I had similar issues to yours.  I'd suggest pulling that harness and checking with an ohm meter.

[junya92toy]

Just get a battery disconnect

[BigBluePile]

I too have had this issue.  Changing the alternator seemed to fixed it.

Sent from my 0PJA2 using Tapatalk

[Craignmz]

Like a woman I am going to dredge up the past!  Lol 84 Runner with fuel injection set up from an 87, I am pulling 63ma parasitic draw.  What would be considered the limit on such an old low electronic vehicle? 

[emsvitil]

Try to isolate it more.    The only legitimate loads I can think of are ECU, clock and alarm if added.

Not sure about an 87 toyota,  but I've seen cars that have an initial parasitic drain that drops lower after awhile.

[Craignmz]

I pulled fuses under the hood and it didn’t change the draw.  I haven’t done any under the dash.  I am thinking the alternator I just put in is my issue (the awesome life time autozone garbage), I will unplug it and check the draw since this all started right after I swapped that out.  But my original question still stands, what is an acceptable amount of draw?  It took 3-4 weeks at 63ma of draw to bring my battery down to 6v.

[Gnarly4X]

I pulled fuses under the hood and it didn’t change the draw.  I haven’t done any under the dash.  I am thinking the alternator I just put in is my issue (the awesome life time autozone garbage), I will unplug it and check the draw since this all started right after I swapped that out.  But my original question still stands, what is an acceptable amount of draw?  It took 3-4 weeks at 63ma of draw to bring my battery down to 6v.

Depends on the vehicle - but from 5 to 25mA on older vehicles, newer vehicles between 50 and 85mA.

Finding where the draw is can be tricky.

I put one of these on one vehicle until I found the draw.

https://www.amazon.com/Battery-Disconnect-Isolator-Horizontal-Vertical/dp/B07Z4R7W2D/ref=sr_1_9?crid=1CIYVXVVFA4A1&dchild=1&keywords=top+post+battery+switch+disconnect+switch&qid=1628818505&sprefix=top+post+battery+switch+disconnect%2Caps%2C251&sr=8-9


Gnarls.