[navy-ad3]

i got a 94 mustang gt. the battery meter jumps around the alternator is newer but the battery is a cheap pep boys special i cant figure it out lol hopefully someone know what the problem is i really appriciate the help thanks

[nolife]

Usually means the battery is weak or old or the battery terminals and wires are corroded.
With a good battery, wires and a good charging system, the difference between the alt output and the battery voltage should only be 1 or so volts which will cause small fluctuations. As the battery gets weak or the terminals get dirty, the voltage difference is larger and the "voltage" fluctuations get larger. Try sitting at idle and turn the 4ways on, see if it is jumping with the lights.

In general, there is nothing wrong with a Pep boys or a cheap Walmart battery. Batteries are wear items, you may just need a new one or your terminals and wires checked.