Hello: I recently purchased a 1982 F-150 302 cubic inch motor automatic. I noticed that the alternator gauge on the dasj jumps cconstantly when driving?.

I am going to take all connections off the alternator and clean contact surfaces. does any one have an idea if this is the gauge on the dask or other problems. The head lights dont flicker or any thing like that. I'm preparing it to be road worthy. Any suggestions would be greatly appreciated thank you.