Dodge Caravan uneven idle?

[JeJe]

I have a 1999 Grand Caravan with over 125,000 miles and it has recently been suddenly accelerating for about 15 seconds then going back to normal. Even when in park, it will suddenly increase rpms for 15 seconds then back to normal idle speed. What might be the problem?

 

[Will1]

hmm..it might be something electricle..when u turn on air-conditioning it does this so it puts out more electricity from you alternater..your battey could be sucky or something and is trying to recharge it or your fan could be kicking in