When it's cold outside my brake & battery light comes on until my car is warmed up and then it goes off. I had this problem last year and replaced my alternator because that is what I thought that meant...

Does anyone else have this problem and if so, how did you fix it?

 

Battery and brake light on means charging system problem.
Measure the voltage at the battery when the lights are on.
If you don't have 13.4 - 14.5, your alty is not working when it's cold.

 

i had the same problem, but it led to a total system failure while i was driving, i checked both the battery and the alternator, both were good, i also checked that the battery cable was not shorted out in any way. that could effect your charging too..mine was good and the next day my maxima started up after my battery was charged....it never did that before......check your battery cable. maybe shorted or bad connection

 

can you explain this more... a total system failure, how did you fix this after it happened?

my lights have been coming on for a few months now with no problem. If it's warm the lights don't even come on. I would say around 32 degrees and below it happens. thanks for all the responses so far.

 

check your belts & connection to your battery. if you have loose belts or slipping belts it will cause the alternator to undercharge/not charge. also if you got a poor connection at the terminals then it would cause that also but i dont see how a temperature change will cause that.

 

Also, check and make sure that you don't have a "maintenance" type battery. I swore up and down that mine was "maintenance free" until one cool night when my car wouldn't start. I popped my hood and staring up at me was the OEM "distilled water" battery. Also, check the obvious your brake fluid reservoir.