Hurtin4Hp

My voltmeter always runs high, almost on the line between 13 and 18 volts when the car is running. Is that a sign of a bad battery? The reason I ask is that when my electric radiator fan(single fan system) comes on my engine runs rough and I am wondering if it is because my battery is no good and the fan is causing a drain on my electrical system. Also, I've noticed that my interior light will flicker sometimes when my car idles. The alternator was recently rebuilt by a very reputable shop and I witnessed it put out over 105 Amps when they tested it. I did blow the fuse in the fan a couple of times and ended up putting a larger fuse in it(I think either a 25 or 30 Amp).
The car starts OK but I have a gear reduction starter on it. It cranks after a couple of revolutions when cold and after 4 or 5 when warm.
I may be looking in the wrong place for the rough idle/running problem but it is the only correlation that I have found so far.
Thanks

[This message has been edited by Hurtin4Hp (edited January 08, 2001).]