Is there away to test aux battery with out pulling it

[LiftedrubiconJT]

Is there a way to test the aux battery without pulling it. I want to have autozone test

Sponsored

 

[LostWoods]

One of the leads to main battery(-) is from the aux battery and I believe one of the red leads to the power box is aux battery(+). You can tap those two and likely do some testing but you'll need to pull a diagram to determine which two.

 

[LiftedrubiconJT]

So it’s best to just pull the aux battery out to have it tested ?

 

[LostWoods]

Best, yes. Easiest, no. It's always better to test batteries directly than through wire but not by any measure that matters (assuming the wire is fat enough which these definitely are) and it's probably an hour to get out and back in assuming you know what you're doing and if you screw up in removing the power distribution box, it's going to get really expensive really quick.

From what I can tell, the aux(+) connects to N1 and N3 on the power distribution box... those would be the first and third most forward terminals but I believe they have the numbers stamped on them. The aux(-) terminal I believe connects to the post hanging off the main(-) terminal. If you disconnect all of those, you should be able to test via the leads in about 5 mins of work.

 

[rubiusgladius]

It depends on where the power control relay is in its position. Whether it has the aux battery in the loop or not. Have to pull it. Also I wouldn’t do a load test through the PCR. Just maybe a voltage check.

 

[aldo98229]

If you are having electrical gremlins and suspect it is because one of the batteries is not keeping charge, check the main battery and rule it out. Then you will know it is the auxiliary battery causing the problems.

If the main battery is in its last leg, I’d replace both batteries in one pass.

There’s no point in going through the trouble of removing the auxiliary battery, testing it and putting it back in. Once you have it out, might as well go ahead and replace it.

 

[jebiruph]

Disconnect both cables from the main battery negative terminal. One of those cables will be the body ground, the other connects to the aux battery ground. Then you can connect the battery tester to the main battery positive and the disconnected aux battery ground to test the aux battery.

Sponsored