Battery Charged, Runs if jumped, won't start no lights / electrical
Latest problem is as follows: battery is charged and car will run. I was able to start it this morning and go to work and almost get back home. Stopped at the store. In the parking lot I put the key in no lights appear (no dash light, no buzzer indicating the key is in the ignition, nothing electrical works).
I got a jump by AAA and the thing started and ran fine even idled. Guy said my battery was just fine (but he was in a rush, so who knows). I ran it for about 10 minutes driving home. Once I get home I turn it off and that's it... no interior lights nothing electrical will work.
The battery reads 12.80 on the voltmeter.
While driving home I noticed the headlights flickering ever so slightly and I tried to use something that runs directly off the battery (ooga horn) and it made about half a second of noise before dieing.
Normally I'd just go get a battery but the AAA guy said mine was just fine.
Any ideas? I tried putting the voltmeter to the large fuses under the hood and got nothing.
1. What is the reading on the voltage gauge on your dash? You should have between 13.5 and 14.4 volts and always best to verify this with a meter and one lead on each post of your battery when engine is idling. The above quick and dirty test will give you a basic idea if your charging system is working properly.
2. Don't trust your AAA guy on the battery. The ONLY accurate way of determining battery condition is to have it "load tested". Voltage testing by itself is often inconclusive and misleading. Any parts store will load test your battery for you for free. How old is your battery?
3. Never a bad idea to freshen all engine grounds; very important on any vehicle. Here is more on that.
Good luck and keep us posted!
Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea, and the investment of your time in this procedure is always well worth it!
You can't tell much of anything by looking at ground connections!! You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. Be sure to remove all paint from any ground connections.
Start with the one on the back corner of the head, and where it attaches to the firewall, as it deteriorates over time and is an area that makes it susceptible to damage. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.
Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.
If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche Without "data", all you have is an opinion!
I've had this happen before after the battery ran down. Drove me crazy trying to figure out the problem until I finally replaced the battery. After it died, I had the battery on a battery tender until it was solid green (fully charged). Car would still have trouble starting and idling. After I finally gave up and got a new battery it has been fine.
The voltmeter on the dash, however accurate that is, showed 14 on the way to work and slowly crept down to around 13-13.5 where it normally is. Of course this is a guess since it's not labelled other than 10 and 14. After getting jumped by AAA the dash voltmeter again read 14 the entire way home.
The battery is a AAA "650" cold crank amps I got in 2010. I killed it once (dome light) before...
Thanks - I'll look at the cables, overall there is not much corrosion under the hood, the battery terminals are shiny silver from when I cleaned them off, the terminal cables don't look corroded but it's possible there's a wire somewhere that is just rotted apart.