Doesn't the speedometer needle indicate if you're moving?

[GPster]

I have a '98 Chevy Astro van in my driveway because the "For Sale" sign can be read better from there. I picked it up from another place for my wife's friend because there where no inquires on it while it set there. It had to be jumped to get it to start but I was not surprised. It has not been in normal service for a while and I thought that I would start by bringing the battery up (charging) before calling it a bad battery, bad alternator, slow discharge through the electrical system etc. Charged it for 20 hours and my charger had gone down to "trickle" mode and the voltage meter on the dash read at 14V. Started it up, no problems and volt gauge went to 16V, ran there for a while and then settled back down to 14V (this was yesterday). Today planned to move it to the front of the driveway and rather than start/shut off I let it run for awhile and even reved it up a bit to watch the volt gauge settle back down to 14V. With the van still in park the speedometer went up to 15 MPH while reving the engine a little. At idle it came back to 0 and while it warmed up while reving you could watch the speedometer needle start coasting down but I didn't wait to see if it would find 0 at RPMs I just let it idle and when the charging indicated it was back at 14V I moved it and shut it down. I don't want to be the seller and the friend has inherited this thing because she was the co-signer. Is this the way things work or does she need to have this thing "scanned"? GPster

[tomslik]

I have a '98 Chevy Astro van in my driveway because the "For Sale" sign can be read better from there. I picked it up from another place for my wife's friend because there where no inquires on it while it set there. It had to be jumped to get it to start but I was not surprised. It has not been in normal service for a while and I thought that I would start by bringing the battery up (charging) before calling it a bad battery, bad alternator, slow discharge through the electrical system etc. Charged it for 20 hours and my charger had gone down to "trickle" mode and the voltage meter on the dash read at 14V. Started it up, no problems and volt gauge went to 16V, ran there for a while and then settled back down to 14V (this was yesterday). Today planned to move it to the front of the driveway and rather than start/shut off I let it run for awhile and even reved it up a bit to watch the volt gauge settle back down to 14V. With the van still in park the speedometer went up to 15 MPH while reving the engine a little. At idle it came back to 0 and while it warmed up while reving you could watch the speedometer needle start coasting down but I didn't wait to see if it would find 0 at RPMs I just let it idle and when the charging indicated it was back at 14V I moved it and shut it down. I don't want to be the seller and the friend has inherited this thing because she was the co-signer. Is this the way things work or does she need to have this thing "scanned"? GPster

a lot of gm stuff does that.
it ain't broke...
seriously.

[sedanman]

I had a 93 Astro van for 11 years. Sometimes it would do that, it was almost like the speedometer was a tach. Kind of freaked me out the first few times it did it. Mine would go all the way up to 60 or 70 miles per hour in park when you reved the engine. Strange..... to say the least  

Sedanman

[GPster]

Thanks! It hits our local shopper tomorrow morning. Now, I know it's safe to stay home. I was going to go pray for it but it's Lent and my intentions might be misconstrued. GPster

[jaybee]

I wonder if the needle just "free floats" on its pivot without a return spring, and without any electrical input (speed signal) the vibration causes it to rise off the pin?