I was wondering about just jumping my vehicle with just the grounds. To see if i need to add a ground strap or my ground straps are going bad. Is it just as simple as just connecting neg to neg not connecting the positives at all. Or is there something else?
Adtr
It tries to start yes just wont turn over. Everything in car works, lights headlights aftermarket stereo and two car amps all come one just will not turn over. Atterybis about 5 months old and when tester battery,alt,starter all come back as fine. The car has sat for about 2 days and everything comes on as shoild just wont turn over. So i dont think anything is draining battery. Just doesnt have enough juice to turn over. And its been about 5 days it does this. When jumped with another car turns over no problem. With only beimg connected for a minute
If it was a gailed battery though would it be completely dead with not starting for a few days. And not sure wasnt there when they tested. and when jumped its always battery to another batteries neg post never to my ground. Bot sure where that ground is located on my vehicle
I've seen some batteries fail in interesting ways.... i had one that worked intermittently. I figure it had a break in the main connection inside that fed the post. Give 'er a little tappy-tap-tap with a hammer, and it would work for a day or two..
I've also has a few with internal shorts.... the constant vibration and abuse evidently caused a couple of the plates inside to make contact. The internal resistance would cause it to drain slowly overnight. Put it on a charger, it would charge and test fine, but overnight, it'd be dead in the morning.
Bottom line, if your battery is not brand new, just swap it out, it's money well spent. Keep the old one around until you determine if that was the issue, if swapping the battery fixes it then the old one is junk, return it for your core.... if it does not fix the issue, it's one less thing you need to consider, plus you have a shiny new battery, and a spare that you can use for other things (get three of then, and I'll tell you how to build a portable DC stick welder.... well not THAT portable).
The other likely culprit here are the Jeep's battery cables. They are crap at best. The stock terminal clamps are an engineering travesty. Basically I see three potential issues with the cables. The battery clamps are crap (see above) and are not making good contact. Try to rotate each one by hand around the mounting post.... if you can move it, it's not tight and not making good contact. Try removing the negative one first, then the positive and clean them up, maybe polish the posts with some emery cloth, to see if you can get them cleaned up and clamping tight. Be careful to remove the negative first, so that you don't toast a perfectly good wrench/socket by shorting the positive against something.... That will scare the beejeebus right out of you and make a pretty spark show. On the bright side, you might just burn it to the ground and use the insurance money to buy another.... win-win.
The cables also have another end..... trace them from the battery to wherever they go... the negative one runs to a ground somewhere likely either on the frame or on the engine block (maybe both) check that each connection is tight. I cannot remember where the positive one goes.... sometimes directly to the starter, but on your jeep it might run to the TIPM (or maybe both).
Long post, I know, but lastly, the cables themselves can be broken internally, usually right at the end terminal points. Fatigue, vibration, work hardening, and thermal cycles can make the copper inside brittle, and it can break inside the insulation jacket. it may look fine from the outside, but it's knackered on the inside. Sometimes you can diagnose this by bending the wires a bit. it will bend much easier where the cable has failed. There is also sometimes a heat stain, or melted bit, as the cracked conductors can cause higher resistance and get hot.
Check the cables, swap the battery and report back. Also, any further detail on how it behaves might help....
Does anyone make quality replacement battery cables for these things? All of this reminds me of how much I hate the stock connections, and I have two new batteries setting on the workbench ready to go in. might be a good time to replace the stock cables/terminals.
Edit: I found these
https://www.custombatterycables.com/jeep-wrangler/
Also a couple of handy diagrams that show where the battery wires go for the OP to check.:
![Image]()
![Image]()
I should mention its not a wrangler not sure if that matters seems like i may have a draw somewhere. But nothing has changed since i bought the new battery but adding an amp and as i tested earlier today they shut off like normal. And for about 5 months after buying a new battery it started to die slowly again. It worked flawlessly for those 6 months
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
