I replaced my main battery last year with an Interstate AGM manufacture date was 2021. Ran pretty good in the summer but now that the truck is sitting in the cold a lot I notice that it doesn't crank as strongly. I hooked up my scanner and get 7.83-7.90 volts when cranking. That seems pretty low to me, anyone else see a higher voltage when cranking in negative-degree weather?

 

Do you mean have the battery load tested outside of the vehicle or is there a dealer procedure to load test the vehicle? I read no other fault codes on other modules, could it be a faulty battery?

 

Charge your battery then have the battery load tested. Should be able to do the test using the lugs under the hood.

 

Charged to 12v (20+min drive)

Tester shows 12v:




Load test shows in the weak range, around 200 CCA. Defective battery I suppose..