need help on electrical problems ASAP!!

[tacomabanga1986]

i need help on tryin to diagnose whats causeing my cuzins lights to hella dim, its a 2000 somethin lexas ls300 and said that she took it to a few shops n they checked the alt n said it was good, that was my first thought was a bad alt, n then shes got a factory battery with factory shit terminals n was wondering if thats wut it is

we live up close to the mountians n she works in the mountians n it might halfto do with cold weather but i unno

she said it would crank up fine but when she starts driveing it would jurk n then cut off, she thinks it might be a timeing issue but i unno,

im a jack of all traids but a master of none so i come to the great smd so see if yall might kno of why its doin this

i need somewhat of an answer ASAP cause she gunna be here in 10min n ive checked everything n i dont kno

would corroded battery terminals cause a car to cut off?

[keepinitloud]

I think that would be a good start check the terminals and check the wires sometimes if the terminals are coroded it can travel back up the wire worked on astro van thought the starter went out put a new one in still wouldnt start went back through everything to see if i had missed something eventually I checked the ground wire and positve did a resistance test found the power wire was bad put a new one on put the old starter back on the van fired right up

[tacomabanga1986]

ya i was thinkin terminals too, she said it would crank fine but when she drove it the lights dimmed n the car shimmied n cut off, that makes me think alt but she had it "checked" and it checked out fine

n i put my dmm on the battery n it was around 12.9v n then had her crank it up n it went to 14.x and was fine

she said her tail lights more flashed than dimmed n im thinkin somethin along the lines of an alt problem to make it do that or feedback threw starter but i unno

i tryed tellin her im not a mechanic but it dont work