I was driving my '88 F150 (XLT, 4x4, 351, C6) the other day and the speedo did this crazy thing. It was reading the right speed and I heard a sound like "plink", and my speedo was buried... it was pointing around the middle of the odometer. I was doing abot 50 mph when it happened. I continued to drive the truck, and then the needle started to move back down to where it was supposed to be. It was really slow and then it settled down to about 35 mph which was the speed I was going when the speedo corrected itself.

Anyone ever had this happen to them? My old Ford Tempo used to to do that when it was really cold outside, but the day this was happening it was about 20 above. Not t-shirt weather, but it had to be a lot colder than this to affect the Tempo's speedo.

One other thing, when the truck's speedo was burried, you could see the odometer turning on both the trip odometer and the regular odometer. They were moving at what I would think would be a reasonable speed for what I was going, so because they were turning, I'd doubt there'd be odometer problems.

Anyway... anyone care to guess at what's going on? The speedo is working ok now for the moment.