When I am driving, sometimes the brake and battery light turn on at the same time for like 1/4 of a second and then turns off. It happens once every few min and usually happens when I am on the gas.
The only thing that I changed before this started happening is I installed coilovers, and I hooked up an air/fuel gauge to the O2 sensor. The gauge had been installed to the cars electrical system for months and turned on and everything, but I never got around to actually hooking it up to the O2 sensors. The lights never flashed until after I put on the Coilovers and finished connecting the a/f gauge.
I do t know if those modifications have anything to do with the lights or not but either way could somebody help me understand what they mean and how to fix it ?

 

OK, check a few things. The first, easiest and cheapest thing to do is check your battery and alternator connections. A loose cable can cause this exact issue. More likely the battery just because of the way the connection is.

If that's not it, then I suspect this is your alternator crapping out. You can sometimes take the car to OReilly's or an auto parts store and they can test it for you. At least at the one near me, you have to take the battery out and bring it in to be tested. I think you have to do the same with the alternator, but go and check, or give them a call.

I don't think your coilovers or the fuel gauge are the issue, but I'll wait to hear once you've check for loose connections and tested the devices.

 

You should also disconnect the gauge and see if the problem still persists.

 

i fixed it it was the voltage regulator in the alternator. Changed the alternator and it fixed the issue. Thanks

 

today the light started doing its thing again. Maybe I got a bad alternator, idk. It was a rebuilt one from orielleys, so i don’t know if it’s possible that the new one I put in is bad. I’m going to use a multimeter to check for overcharging and see.

 

O'Reilly sells good stuff generally.
If it was from Autozone, then I might be wary of it.

 

Only offering anecodotal. It was not for my G35, but I had to go through 3 alternators from Oreillys for another car last year that needed a new one. I finally ended up returning the 3rd and taking my original OEM alternator to a alternator repair shop, where he fixed it and that went back in the car. 20,000 miles later and it's still fine. that's my goto route now, rebuild the OEM.

 

wow..so much for O'Reilly's
Sad to hear.

 

It wouldn't surprise me if they get their components from the same vendors.

I suggest finding a local starter/alternator shop and just having them rebuild the OEM components. Alternators are just bearings and a voltage regulator, local shops are typically sourcing quality components.

Plus it's usually cheaper.

 

Completely Aside:
Wife and I were at a car show.
Mexican guy shows up asking a group of us about who in the area could rebuild an alt.

Those around us dismissed him and said to just get a new alt. at a **** store.

I asked him why he needed an alt rebuilt.

He, now Jorge, said he needed the OEM rebuilt because it was going back into a (BMW) spyder 1000(?)..can't remember..one seater. OEM parts are essential and even rebuilder is part of the car's record, resume and DNA.

Jorge said his boss sold the race car to the new owner, and lent ( gave he says) him a free Mexican mechanic to get it running.

Jorge got his start by rebuilding a Porshe 911 while in HS. He got his first job working under an Italian Artesian at a Porsche shop. He learns to hear what a Porsche needs by simply listening to her.

A friendship was made...even though I lost track of him.

I see him in my mind smoking a cigar with the original Spyder owner at a vintage race in Europe somewhere..a millionaire in his own right.

Time goes bye...

Yup.

 

I'm honestly surprised it's not a more common practice to rebuild your own alternators. Heck on most cars the hardest part is just removing the alternator from the car in the first place.