Voltage gauge

[bluesboyst]

2003 Marauder: the other day I noticed when I put my foot on the brake my voltage gauge needle moves to the left quickly then back to 14 volts. If I have my rear defogger on and come to a stop light the reading goes to about 8 to 9 volts and the lights flicker....once the RPM's go up it goes back to 14 volts. The battery is about 2 years old. Could this be the alternator going bad?

[RubberCtyRauder]

test the volts at battery with a volt meter while off and then idling and then turn on some accessories.

[bluesboyst]

Did that... with engine off voltage is about 12.6 volts....start engine it goes to about 13 volts. turn on accessories is goes to about 12 volts or less

[Spectragod]

13 volts at idle is too low, should be 13.8-14.4.

[RubberCtyRauder]

symptoms suggest alternator to me. marauder ones are specific, 4G style. crown vic ones do not work

[RubberCtyRauder]

but make sure you have good clean connections and grounds. corrosion on wires can effect it.

[ByronRACE]

Check voltage between alternator case and main alternator power stud while running.

[RF Overlord]

but make sure you have good clean connections and grounds. corrosion on wires can effect it.This. ^^

I had all sorts of electrical gremlins in my Grand Marquis. Ended up replacing the battery terminals with these (https://shop.advanceautoparts.com/p/autocraft-repair-cable-universal-top-post-4-gauge-black-ac164t/11142551-P?krypto=KHd6VOSOIX7j%2FiUr2ZM T4gRexgByk64yV4THcg9iXmqE3M2L% 2Ff%2FSp4p%2BBENy%2BoBcpQPwHjT S7KTdc4iH8itBiA1CQ8H1HUUQT75jG PYis9NYbGBLLwMgT%2Fgg7PZl69KCv XdHuvd6P0EVH%2BZnL09xpJ8XsBfnl TZb5qe3Xtu7QjIteA3K2GXzshxBohX T3Ee5) and ALL the issues went away.

[bluesboyst]

I found the issue.. was a loose connections at the battery....
Thanks all