Big Green11

Ok, so 2 years ago I had issues with my batteries dying in the winter when the grid heaters kicked on for quite a while. So I replaced the batteries with some Optima Red Tops since the others were old and due for replacement. Since then I have replaced all battery cables and rebuilt the starter and the problem has slowly gotten worse. Even if I let my truck sit for an extended period of time now it seems slow to start.

Well this morning was the last straw. 55° F outside this morning, went to start the truck, grid heaters kicked on for a second, dead as a door nail, wont even turn over. So I get out the charger, juice the batteries up and away I go. I know the grid heaters draw a lot of current but thats why we have 2 batteries. There is no reason my batteries should be getting drained that much to the point where I cannot start my truck on a mild weathered day .

So here are my thoughts, either my alternator is dying a very slow death or I've got an electrical leak draining my batteries when the truck is off. I am getting a good 14.8V reading from the dash gauge which has kept me from investigating the alternator but after a battery/cable/starter replacement I am having my doubts.

Anyone have any similar experience? What are your thoughts?

patdaly

Some Optimas are not lasting like they should, Mexican built ones if I remember right. Charge them fully and do a load test, bet one or both fail.

Purplezr2

You should be able to measure the amp draw with the key off it you have a multimeter.

DodgenIt

Couldn't hurt to replace the alternator.
I had my optima reds drain and die suddenly in a few days a while back, all I did was clean the terminals and all connections and they've been good since. Doubt this will help as I'm sure you yours are clean if you'd replaced cables.

Copenhagenjunkie

it could be the seat belt timer box under center of front seat draining the batteries.

Ed ke6bnl

I never really found out way both my boys and mine will kill batteries, honestly did not do all the amp test I could but I have a maintainer on the battery and plug it in all the time and no issues, I now that is not the best answer or for everyone.

SIXSLUG

I would start by getting both batteries load tested. Just because you spent a fortune on batteries doesn't mean they are good ones.

If they pass get a multimeter and check for parasitic drain. If you are pulling voltage off them with the key off etc, you can then go to things like the seat belt timer, radio, etc. to see if something is drawing off your charge.

Since I converted my power windows for key off operation I have a slight draw from the switches illuminating but it is negligible.

ericg

+1 on checking the batteries. Had optima red tops that only lasted a year. I would charge them up and they would only hold a charge for a little while. I replace them with auto zone batteries and the problem went away.

megajoltman

Replace my little over a year old red tops with interstate batteries no problems since (2 1/2 years)

Big Green11

Looks like the problem is in the dash, haven't narrowed it down just yet to exactly what circuit/component it is, but something is draining the batteries with the key off for sure.

Big Green11

Scratch that, looks like everything is working properly including the seat belt timer. Now its either got to be alternator or batteries.....

Big Green11

Test last night showed a bad alternator diode. Replaced alternator so we'll see now if that is the fix after I get a good charge on these batteries.