Whenever I hit the brake on my 96 LT-1 my main orange LCD screen on the dash dims, is this common, or perhaps a voltage drop from a weak alternator? Regulator?
Does anyone else experiance this problem?

 

Does the volts gauge drop as well? IMO The alt would be the first thing to check, second the battery. Sudden loads on the battery can cause the voltage to drop. Let us know what you find out.

 

Same problem. I replaced the alternator and all is well now.

 

Could be several things, loose/corroded wiring at alt/battery, or battery. If it is the alt you should seeing other symptoms as well. I would check alt and battery connections first then go from there.

 

You need to determine if the voltage across the battery drops when you put the brake on is due to a failing voltage regulator in the alternator. An easy test is to put the ign sw in the run position without the engine running and then press the brake. If the dash dims, then the alternator is not the fault. If the alternator isn't the problem, I would first remove the battery cables (neg first) and clean the cable lugs, bolts, and the battery terminals and replace the cables (neg last). Try the experiment again and if the dash still dims, you will need to find out where the voltage from the battery to the dash is dropping when you press the brake. First, with a digital voltmeter (Harbor Freight for $7), see if the voltage at the battery drops when pressing the brake, then see if it drops at the brake fuse. Power gets to the fuse block through a fusible link, then through the connector on the firewall, then to a large splice in the wiring harness behind the dash where individual wires go to about 6 individual fuses in the fuse block, one to the brake fuse and one to the dash display. Any unusual resistance in the connections from the battery positive cable, fusible link, firewall connector, or the splice can cause your dash to dim with brake applied.

 

I have the same problem in my 95, except it also dims if I gun the engine & the rpms drop back to idle.

 

Do you have a larger pulley on the alternator to reduce parasitic load? The alternator has a limit on how low its rpm is and its ability to supply current. At normal idle speed and without an excessive electrical load, the alternator should be able to maintain 14.3 volts (dash voltmeter) across the battery. You may have a defective voltage regulator in the alternator. You can replace the regulator or the alternator. The regulator is cheaper. You can have the alternator tested for output at low rpm too.

 

This only happens for a split second after it drops back from a high rpm, I think I'll replace the alternator, save me the time to polish up the old one.