electrical problem!!!

[300ZX90NA]

for a couple of days my car has been acting strange i will be driving and i step on the brakes and all my lights dim and my stereo turns off and turns back on and sometimes the car would be stuttering like its about to turn off and the rpms wont go higher than 1500 and when that happens i park and turn off my car and it wont turn back on i have a jump box and after i hook it up it will turn back on i was driving on the freeway and my car turned off on me just lost all power not even for the emergency lights after an hour of sitting on the side of the road trying to jump it with the jump box i still wasn't getting any power i started looking under the hood to see if there was a bad connection or loose ground but couldnt find anything...i don't know what i touched or what i did but all of the sudden all my power came back on and i was able to drive it home i took the battery out to get it tested and its a good battery does anybody knw what could be the problem or give me an idea as to wear to start looking to find the problem please thxs

[Zwicked]

Have you checked your battery terminals to make sure they are clean? Also, let the car idle once the terminals are cleaned, and test between the pos and neg terminals with a multimeter to make sure the alternator is ok. It should read about 14.2 volts.

[DanDrath]

I finally figured out the electrical problems with my car. It was the wiring harness shorting out. Check your wires to the things that arent working rite maybe the wires are shorted out

[evildky]

an recent wirign? aftermarket stereo?

if nt, take off the rear interior panels, most likely you have a broken ground and the tails are groundign through the illumination circuit

[mstaat]

my positive terminal conecter broke and each time i would step on the brakes my stereo would turn off and the same when i would turn the brights on

[jz1992]

I had the same exact problem ...my car one day while on the road sunddenly shuts off when i would flip the key thered be no reaction i wasnt getting any power inside , no dash light, nothing. i waited there for about 2 hours and it suprisenly stared..everything worked fine and i ran it as is for about 3 weeks until it happend to me again ..this time it didnt start working again..i hired a mechanic and he said i had a wiring problem threw the bottom of the car..he says i might of hit a speed bump or bottomed out??

Good place to start looking.

[300ZX90NA]

the same thing happen to my car i was driving and everything turned off i was sitting on the side of the freeway for about an hr when all of the sudden all the power returned drove it home and the next day drove it like nothing ever happen jus that when i would hit my brakes my gauges would jump and the stereo would turn off what was causing this was the alternator going bad i replaced it which took me like 8hrs to figure out how to take it out but put a brand new one in and that problem hasn't happen again