Will a bad battery make my rig run weird???

OK last night my jeep's headlights kept dimming, radio shutting on and off, and power to the motor would be lost for a split second, only to immediately come back on. Shut engine down and it would not restart but the electrical system was going hay wire!!

It's a 4.0 96 XJ AW4. All grounds are excellent.

I have a Blue Top deep cycle Optima battery that's 3 years and 4 months old.

I jumped the jeep this afternoon with my truck and it'll start right up and stay running, although the headlights randomly get dim and then bright again. Put a multimeter on the battery w/ the jeep running and it shows 14 volts.

Turn the jeep off and it wont restart. Multimeter back on the battery and it reads less than 9.5 volts.

Am I correct in assuming my battery went bad??

A bluetop is not the best choice for a daily battery. Yes, your battery can cause all kinds of mischief, the alternator as well as the Power control modual can cause havoc. Best bet is take it to autozone or some other chain parts store, even Sears and have them put the tester on it.
I run red tops in all my jeeps.

RichP said:

A bluetop is not the best choice for a daily battery. Yes, your battery can cause all kinds of mischief, the alternator as well as the Power control modual can cause havoc. Best bet is take it to autozone or some other chain parts store, even Sears and have them put the tester on it.
I run red tops in all my jeeps.

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I have a winch and a lot of lights so I wanted a deep cycle in there........

sounds like an alternator to me.

If you put a meter on your battery while not running and it reads 9.5 volts, then yea....the battery is definitely the thing to suspect. Batteries can crap out early; no guarantee on long life of them. You can have it load tested to be sure but I think the meter tells the story and you're probably going to be battery shopping.....

90Pioneer said:

I have a winch and a lot of lights so I wanted a deep cycle in there........

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People I know that have that kind of setup run a red top as a starter battery or a yellow top, the blue top is kept as the winching battery, some run two yellow tops or a yellow top and a blue but no one I know uses a blue as a starter battery.
There is a fairly good discussion on it here:
http://groups.google.com/group/rec....luetop+for+a+starter+battery#a36c52fa8c59fa80

Interesting to note that optima only lists one model blue top as a starter battery, an M model.

RichP said:

People I know that have that kind of setup run a red top as a starter battery or a yellow top, the blue top is kept as the winching battery, some run two yellow tops or a yellow top and a blue but no one I know uses a blue as a starter battery.
There is a fairly good discussion on it here:
http://groups.google.com/group/rec....luetop+for+a+starter+battery#a36c52fa8c59fa80

Interesting to note that optima only lists one model blue top as a starter battery, an M model.

Click to expand...

The deep cycle blue tops are the same battery as the yellow top except they have auxillary mounting posts. No other differences. I assume the same is true for the M model of blue top vs the Red Tops....

I don't have room to run dual batteries....

x2 on alternator.

every single car on the road has a battery, steal one, throw it in the xj, if it cures the problem, its the battery, simple.

batterys go out... and they dont allways just die... sometimes its a long agonizing death.
i could still be running my old battery, IF i wanted to deal with zero shelf life on the charge...

90Pioneer said:

OK last night my jeep's headlights kept dimming, radio shutting on and off, and power to the motor would be lost for a split second, only to immediately come back on. Shut engine down and it would not restart but the electrical system was going hay wire!!

It's a 4.0 96 XJ AW4. All grounds are excellent.

I have a Blue Top deep cycle Optima battery that's 3 years and 4 months old.

I jumped the jeep this afternoon with my truck and it'll start right up and stay running, although the headlights randomly get dim and then bright again. Put a multimeter on the battery w/ the jeep running and it shows 14 volts.

Turn the jeep off and it wont restart. Multimeter back on the battery and it reads less than 9.5 volts.

Am I correct in assuming my battery went bad??

Click to expand...

i think i might have a similair problem with my 89 xj


first off mine starts fine ( takes it a few cranks understandibly for a 89 but it always starts) i get my radio shutting off along with the signal lights. My head lights stay on, they will only intermittley dim when its idleing. i have a sirius radio plugged into the cigarette lighter it always shuts off too when the radio dies. The heater fan will stop too.

None of these things die by themselves its always all together and its only happened 5-6 times in the 9 months of owned this jeep. I changed out my battery because of cold weather starting issues a week ago and before that this problem happened like 3-4 times in the week i was having starting issues. It hasn't happened since i changed it out.

i'd like to know what your problem ends up being when you figure it out

jeepster_259 said:

x2 on alternator.

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reasons why you suspect the alternator?

remember I put a multimeter on the battery when the jeep was running and got 14 volts...