Temperature gauge stuck on extreme high , wont come down . I get hot cold air

Hello. Have a 2005 Chevy Venture; Could be two things...may need to put in a new fan blower resister; Cost me $26 on Ebay; installed and now works great. Also...dash gauges can quit working right. Car showed heating up continuously. Found a web site where they show you how to remove gauge panel (easy-within 10 minutes; you send to them in Georgia; I paid them $100 plus S&H; got it back within 48 hrs; OEM, warranty for life; fixed all gauges, lights and returned. Seems Chevy had several recalls on dash back in early 2002's etc. (Not positive on years) but so far working fine for me, and I'm a lady who put fixed my self and saved me over $400 for dealers to put in gauge not including parts and I'm sure couple $100 on the resister. Now A/C & Heater work fine. Any questions leave me a message at sandie1165@hotmail.com

Oh, you can drive your car while gauge is out, you just won't know how fast you are going. Also, the blower resister I'm talking about is up under the passenger side panel. Take down the insulation cover, take 4 bolts out of fan cover, look way to back and see the resister. A pain to get out if not right tools. Laid upside down on floor to get it out; put it back in, buttoned everything up and works fine. Good luck