ok guys can anyone tell me why when i go over 4 grand my battery and brake light start flashing on my dash the brake is down and my voltage is good??? it started happening after my underdive install today.

 

loose connection somewhere, when you rev the engine moves must be shaking something enough to cause the lights to come on.

 

Injectors too big.

 

Are you sure it isnt actually getting back up to normal brightness? It may be under-driving the alternator and at idle or low rpm's everything is actually slightly dimmer? Then you rev it up and the lights get brighter. Put a multi-meter on the battery and check this, it may be a voltage jump.

 

i have stock injectors. i will look at my voltage but i do not think its going from dim to lit because when u turn the key to on but engine off it lights up like its suppose too. i also changed my brakes today im kinda wondering if i messed up the brake cable on accident when i did the back brakes.

 

Make sure the brake fluid isn't low as well.

 

+1 low fluid. no idea on the battery light, check engine grounds and batt/alternator terminals

 

What pulleys did the underdrive kit came with?

Are you SURE you put the one for the alternator on the alternator??

I think that the problem is that you put a smaller pulley on the alternator, making it work at a faster speed than normal. And when you go over 4,000 rpm, your voltage increases and goes over the maximum limit, which makes the battery light flash.

The flashing means to stop INTERMEDIATELY if you want to avoid damage to the car).

Just check what voltage are you getting on the center gauge, and check if you did not mixed the pulleys up.

 

Oh, also check that you actually put the belt the way its supposed to go. It can also cause that issue.

 

+1 on checking brake fluid level.

 

+2 on the brake fluid level. Most electrical gremlins are due to low fluid levels in this car whether that be the brake fluid, power steering fluid, transmission or even coolant levels. Low fluid forces pulleys to overwork themselves in order to use extra force to pump the low levels into the appropriate places of the motor/car. Often times, this puts extra strain on the alternator and causes it to draw current away from your main power supply. This chain reaction usually causes cluster lights to flicker.

 

Wait... by "the brake is down" he means that the pedal goes to the floor? Or that he has no brakes?