Signs of a bad/weak battery?

[Matt V]

The more I notice things, the more I realize my car might have a bad battery. While my car is running, my oil pressure gauge will often randomly spike then go back to the correct pressure, and if I roll my power windows up or down it will spike up and go back to normal once I let go of the switch. My idle will also drop down quite a bit if I turn my headlights on, the oil pressure twitches when the hazard lights/turn signals are on, and every once in awhile my car will have a very jumpy idle. In addition, this cold weather sometimes causes issue with my car firing up on the first crank. I have to give it a second crank every once in awhile.

Would these be the signs of a dying battery?

[Matt V]

Well I replaced the main ground that goes from the chassis to the engine block inside the engine bay. I noticed that it was very brittle, and partially covered in oil. This might be the reason for the issues I'm having, I'll post up more tomorrow after I drive the car.

[AlanP1964]

Ironic because I had just noticed the same thing about my 95. Hit the power window switches, or turn the headlights on and off and I notice a quick drop in RPM.

[Matt V]

Well, the new cable fixed the spiky/twitchy oil pressure gauge but I still have a crappy idle sometimes. Did it twice today actually, some people mentioned a cylinder might not be firing. I'll probably replace my spark plugs and see if that fixes the issue.

[Radio-Active]

How long has it been since you replaced the wires? They are known for breaking down and arching in the valve cover holes every 20-30k miles.

[Matt V]

I have NGK wires with 3-4k miles on them.