hey guys, I just picked up an Evo 9 MR. The car has the Brake and Battery light on full time. The last owner told me it’s been on Sincd he replaced the alternator and has not gone away. I searched all over as I see the brake and battery light is a common sign that the alternator is bad. The car is charging and from what I can see in the MR volt gauge it’s at 14.5. I have checked the fusesble link on the battery and all looks well. Any ideas how to turn these lights off? Is this a possibility of running an aftermarket alternator and the electrical system wanting an OEM? Any info would be greatly appreciated, I don’t want to replace a good working alternator unless it’s the only way to clear those lights.

By the way, I apologize for the typos, just stopped off the highway to make this post quickly and did not re-read 🤦🏽*♂️ 😂

Voltage reference wire that runs from the battery to the alternator. Basically, the ecu saw 9v instead of 12v due to resistance and bumped the charge.

I just put my volt meter to the reference wire to the alternator and it seems to be charging at 15v-15.3. I turned on headlights and Ac and it dips down to 12 and then back up to 15v. Is this due to a regulator issue in the aftermarket alternator?

It is high. So either the regulator, or the reference wire issue like I had would be culprits.

It is high. So either the regulator, or the reference wire issue like I had would be culprits.

ahh okay. Im going to go a bit deeper into it and see whats going on. Thanks for the help Project_Broke! Ill report back with what I find when I do.