electrical issue - dash light

[stune240sx]

I did my 300zx brakes swaps, so after i bleed all the wheel i tried to go for a test drive, but the battery was dead. So i jump start it, then i found the every time i step on the brake, the dash light and the headlights went dim. then i turn the headlights on, the Temp goes way up, but if turn it off, it goes back to normal again.

it is a s13 with redtop SR, and a pc680 odyssey battery. I heard that once the odyssey got drain dead, they won't charge again, is that true?

I am not very good at wiring and electric and stuffs, please give me some idea wt to look for. anything would help.

I changed the alternator, and checked all the ground but it didn't help.

[the converted]

Did you check all your fuses?

[ReX2SX]

No if it was a fuse the circuits wouldnt work. For some reason your drawing too much power.

I see you replaced the alternator but do you know if your battery is even good?

[stune240sx]

i am not sure if the battery is still good, but i just got a new one, i will put it on first thing in the morning. I checked the voltage today, when the engine is on it is reading about 12.5, but it suppose to be at least 13 right?

[zerodameaon]

I had a ground go bad on my 240 with a RB25 swap. did the same things. check your grounds and go from there.

[ReX2SX]

Usually the car should be at 14v running. Off the voltage should be above 12.4v.

But yeah, i wold first make sure all my grounds are good and wires are good.

[stune240sx]

ok, i checked all the ground, replace the alternator and battery.Now when i first start the car, it is reading 11.9V then i rev up the engine and it read 15.8V and stay there. Is this bad?

[ReX2SX]

Honestly you should go by OEM err..JDM specs. 16 volts seems a little too high, like a bad voltage regulator, but since you replaced the alternator you should be fine.

I wouldnt worry too much about this. But do keep an eye on it.

But the problem is still occuring??

[stune240sx]

yes, it is, the light still go dim... i don't know wt to look for anymore.... would that because of the harness, cause when i do the swap, the harness is kinda beat up...