Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 13 of 13 Posts

·
Registered
Joined
·
50 Posts
Discussion Starter · #1 ·
I went to go start my 2008 Wrangler yesterday and had no start. It seemed like the battery was dead but then I checked the voltage and it was full. When I turn the key I get one click and then my dash lighted flick on and off. Has this happened to anyone. I tried to pull both IOD fuses under the hood but did nothing. Pulled the battery connectors off over night, still same thing this morning.
 

·
Registered
Joined
·
233 Posts
Sounds like a bad battery to me....just because you battery shows 12.7 volts it doesn't mean it is good.....with any load it may drop way down. Do you have a known good battery you could swap it with?
 

·
Registered
Joined
·
1,424 Posts
Sounds like a bad battery to me....just because you battery shows 12.7 volts it doesn't mean it is good.....with any load it may drop way down. Do you have a known good battery you could swap it with?
Totally... A nearly dead car battery will still show 12v, but it won't have enough amperage to crank your engine.
 

·
Registered
Joined
·
1,346 Posts
Bad battery or a bad ground somewhere.
 

·
Premium Member
Joined
·
533 Posts
Take the battery to your local parts store and have them load test it.
 

·
Retired Moderator
Joined
·
100,513 Posts

·
Registered
Joined
·
636 Posts
For starters, how old is the battery? If it's original, it may just be time for a new one.

Here's a quick load test for the battery, but you'll likely need a helper to either hold/read the meter, or crank the engine:

Connect a meter directly on the battery posts and monitor it while you try to crank the engine. If the battery voltage drops like a rock when you try to crank, the battery is toast. If not, then you may have a bad (high resistance) connection somewhere that's dropping all the voltage when the heavy cranking current is drawn.

Repeat the test, but put one meter lead on the battery post and the other on the same terminal. Try to crank again. You DON'T want to see much if any voltage here. (This may not seem to make sense, but what it checks is the connection between the terminal and battery post - it doesn't take much resistance here to cause problems due to the huge current that the starter draws.) Do this test for both battery posts/terminals. Again, no or low voltage during cranking is what you want to see here.

If terminal connections are good, I'd next put the meter between the negative terminal and a metal part of the engine block (make sure it's a ground point, and that you have a solid connection.) Try to crank again. You should see little or no voltage - if you see more than a volt or so, you have a bad connection between the battery and ground. If you can get at the hot terminal on the starter solenoid, do the same for the positive lead.

I don't have a jeep yet, and so am unfamiliar with the actualy battery terminals used, but its possible to have a bad connection where the wire enters the terminal itself - checking the voltage drop across the cables can isolate that.

Good luck!

-Pat
 

·
Registered
Joined
·
50 Posts
Discussion Starter · #10 ·
Battery

Thank you everyone for posting answers. I am taking the battery to get bench tested right now and we will see what happens. I really appreciate all the advice.
 

·
Registered
Joined
·
3,108 Posts
Thank you everyone for posting answers. I am taking the battery to get bench tested right now and we will see what happens. I really appreciate all the advice.
If you have a voltmeter you can test it pretty easily at home. Just hook it up and watch the voltage, if it drops significantly when you hit the ignition then the battery should be replaced.
 
1 - 13 of 13 Posts
Top