As per the title. Any ideas what is causing this? I tired twice but the car failed to start. Waited a few minutes and car started fine but rpms rough but then settled after about 10 seconds. Battery volts read 12.7 when car is off. Battery is a few years old.

Car is pretty much stock electrical wise with just a CD player. Alarm arms/disarms via the remote all ok and all lights gauges etc work fine.

Any idea?

 

what type of alarm? your battery sounds fine at 12.7 volts to be honest.

 

Battery may not have enough juice to start the car. Have someone monitor the voltage across the battery terminals, crank the engine. If the voltage drop way low while you are cranking, battery is bad or it need a good charge if it been seating.

 

Hi - it was a dead battery. Took it to an auto store who confirmed the starting voltage was good, but battery had a dead cell. Picked a new one up today and everything is good again

 

Love it when it's something simple.

 

Good to hear an "R" is back on the Road