Hey all,

I was driving home from work and noticed my gauge lights were a bit dim. I thought it was my sunglasses that I was wearing. Also the RPM gauge wasn't working properly. It was running backwards?? Every time I accelerated the gauge would go down instead of up. The turn signals wouldn't flash. Radio wouldn't work at all. I barely made it home and she won't turn over. Could it be my Altenator? I haven't changed it since I've had the car. The battery is 2 years old. I can still turn on my lights. Help! She's my DD!!

 

With engine running the voltage at the battery should be around 14 volts. 12.6 with the engine off and battery fully charged. Purchase a small battery charger and charge it.
It does sound like its not charging though.

 

My brothers (97) jeep sorta did the same thing, it was the battery cables. i would start by cleaning your wires.

 

Battery cables are pretty clean. I tired hitting them with my Club to get a better contact. The car still shut off. I'm gonna pull the battery and have it checked at the auto parts store. I'm thinking its my Altenator... Hopefully not, as I have to work tomorrow. Today has been one of those days.

 

I also noticed it was popping when I would slow down to come to a stop.

 

Well, I took the battery in to the parts store and had it tested, they said it was bad. (It was only 2 years old) So I bought a new one with a 3yr guarantee from AutoZone. (Can't stand their parts, but I needed a battery ASAP) then they tested my Altenator, they also said it was bad. Looks like I'm calling into work tomorrow... While I'm at this, I will be upgrading my fuel injectors to Neon 703s and changing my lower steering shaft since there is a bit of slop in it and upgrading my lower control arms. Grease monkey time!!

 

Just remember when you clean your battery cables that there are 4 ends...not just two.

 

You definitely need to check your grounds! Check connections at the battery posts, and at the connections to the chassis. Be sure to use a wire brush...get the connections SHINY! I would doubt that both battery and alternator are shot...but it is possible. I've not been a big fan of AutoZone...find a local parts shop...not a "big-box wanna-be" type store.

 

Thanks for the replies! I also did my own test. Installed the battery. Turned on the car and pulled off the Hot on the battery. She shut off right away. Did it a few times to make sure.

 

DO NOT use that for a test. If you pull the battery lead off the computer does not see the battery voltage and decides the system will need more voltage. So it kicks the alternator up to 18-19 volts which has the capability of frying the computer or sensors.

Ron

 

Well, I took out the Alternator, ran it down to the parts shop to have it tested. It passed and is good. I was thinking of Changing since its already out since I don't know how old it is. I'd hate to get stuck out in the desert while playing in the dirt. I will also clean all contacts. Any other thoughts??

 

make sure you get a new belt as well...

 

Put it all together then test the voltage at the battery with the engine running. You should see around 13.8-14.5. Often the test done at cheap auto parts stores are not accurate so a replacement is a good idea.
You can get a cheap volt meter from WalFart or other discount house for under 20 bucks. Its a good thing to keep in the Jeep.

Ron

 

Alrighty, I got everything back in place. She ran fine last night. Then, this morning I hopped in to go to work and noticed my Battery Gauge Read at 14 and then jumped down to right above 9 mark (not in the Red). Then my Left blinker wouldn't flash everytime I signaled. Right side was fine.

Could this be PCM problem?? If so, could I pull a PCM from a JY, my XJ is a 2WD Manual 5 speed. Could I use one from an automatic around the same year?? What are the symptoms of a PCM going bad??

 

Suggest using a real voltmeter...not just the dashboard indicator. On my JEEP the dashboard indicator turns off after 20-30 seconds of the car not running...I think most auto parts stores will let you borrow a meter to make measurements in their parking lot.

And...as many have already mentioned...all bets are off...and NOTHING will work if the connections to the battery and the chassis...or the cabling...are not good.

Battery and alternator are electrically connected...so they will always read the same voltage. Battery should read 12.5-12.8 volts with the engine not running. When the engine IS running, the alternator should increase the voltage up to 14-15 volts. (This allows the alternator to re-charge the battery while your vehicle is running.) A different voltage while the engine is running would indicate bad alternator. A LOWER voltage than 12.5 volts on the battery when the car is not running would indicate a bad battery or a discharged battery. (But...a DISCHARGED battery might not be a BAD battery...big difference.) Since your battery is basically brand new...I'd guess that the battery is good...still might be discharged...but will not be a bad battery.