Quote Originally Posted by unity View Post
I checked my coolant and it's at the maximum level. My last service was only 3 months ago.

I have noticed starting my car on a cold night (with electrical load) that the idle suffers (louder(whine?) and rougher) so I was told that my alternator might be struggling with the load.

Is there any other test I can do or any other sensor I can monitor that will give a more definite answer?
Haha, I didn't mean that the coolant would be affecting volatage, just that I always try and stop my coolant reaching 90 or above.

You can just start the car with the radio, lights, seat warmers etc. off until the idle starts to drop a bit. That's what I do and I don't get any of the whine you're talking about.