Battery drain?

[Dezertpilot]

I installed dual batteries a little while back and everything seems to be going fine. Just recently I have been having a hard time starting my 4runner. I have the batteries in the back with a Cole Hersee battery selector switch. I also have a GPS and it tells me how much volts I am running. I tried to start and nothing. I tried again and it wanted to start but I thought Id start ripping the teeth off the flywheel so I let go b4 it started up. Now it wont start up and when it sits for a min it say about 11.2 or so volts and when I turn the ignition even more to try to start it reads about 9.2 or so I think its cause the electric fuel pump is taking away power. Is it possible I have some sorta battery drain? In the morning when its cold it starts up fine, I think my starter is going but shouldnt the volts just sitting there be more than 9.2 volts? I try the yellow top then both even just the yellow but nothing. I should have plenty of juice with either and both batteries.

[gwm]

It's normal to drop voltage when you hit the starter but 11.2 static voltage is essentially dead. Get a hand-held voltmeter and take some readings directly from the battery. Sounds like you've either got a charging or a battery issue. If the battery's good you just have to start tracking it down. Do you get 14 or so when the motor is running? Alt's ok if you do. Are your cables/connections good? check voltage at both cable ends to see if you are losing voltage there. Was the switch left positioned so one battery drained and is now draining the other? It's just a matter of tracking it down.

[Dezertpilot]

I usually just have the switch set so it takes power from the red top Optima. Every once in a while Ill set the switch to Both to charge them both. All the connections seem to be good Ill have to go through it this weekend or in the near future.Oh and this morning I get in and start it up and its fine, drive to work and park it. At lunch I get it to drive it and it doesnt start, on the 2nd try it wants to start but I let go of the key so the starter teeth dont mesh with the flywheel. I should have kept it on longer. Then I try for like a couple of minutes and nothing. I think it even reads at like around a 9! SO then I stop and go inside then come back out and on the 2nd attempt it starts. Why would this happen? If the batteries were so low wouldnt they never want to start the truck?

[ShaneR]

Sounds like the starter to me but that doesn't explain the low voltage reading on the GPS? Do you have a battery load tester, then you could eliminate that as the problem?

[Dezertpilot]

Yeah I thought the starter could have been the culprit still not quite sure. It was replaced less than a year ago but it is not OEM. It is from Kragens I shoulda got the OEM Toyota one but they are generally expensive and the Kragens have a lifetime warranty. But I think their might be a short in the starter possibly. I am gonna remove the battery selector switch and see if I find anything abnormal. But why would the GPS show such low voltage? I looked at my Autometer volt guage when I got in and it was at or near 12 volts then I turned the key partially and it dropped say 2 volts. If I cant get this problem resolved soon DMZ Tim is gonna help me this guy is a genius! Oh and both Optimas the yellow and red are brand new!

[Turbothief]

Hi All, sounds like you have a bad connection to the batteries. Voltage that comes and goes is usually is a bad connection or corroded cable. Ck grounds to batteries also.

[Dezertpilot]

All the cables (2 guage) is new it was installed in the middle of September. I checked the cables going to the battery and no corrosion and the grounds look fine. I am gonna have a further in depth look this weekend. For now I am just turning the battery master switch to OFF and it seems to be doing the trick. But it resets the ECU and accessories every time and I really think this is just a band aid on the elbow for a problem on the foot.

[coooray619]

you may have a parasitic draw from somewhere in the electrical system... put a DMM in series with the batteries with the ignition and all accessories off, you should be pulling no more than 35 milli-amps

[GMCrunner]

WHen you go to start it does it just click once when it wont start.

[Superfab]

Try by-passing the battery switch. Sometimes they go intermittent. I use 2 flaming river off-on switches due to the fact I've had 3 different mfg. switches fail. This way I can switch on a battery with the motor running without hurting the alt. These switches are rated to 2,00 amp surge.

[Dezertpilot]

The problem seems to have gone away. But I kinda think that my alternator isnt quite up to par. Is there a place that will rewind my alternator for more juice? It seem like their is to many accessories and that it is pulling to much juice at idle. But at speed it seems to be fine. My 4runner starts all the time now. I am quite perplexed. I guess I wont know untill I actually get down and investigate the problem. I am being lazy but need to find what cause the problem.