Hello folks. I have an unusual issue with my 1969 speedometer, and hope you can help. I have not worked on the speedo head, but have replaced the cable. The speedometer does not work when first cranked and run. It used to start working about 2-3 miles out during the drive. The distance has slowly increased to the point that I have to drive 8-10 miles before it starts working. Once it's working, it stays working and doesn't bounce. I can stop somewhere, cut it off and come back to the car in 10-15 minutes, and it works immediately at start. But if I wait more than an hour or so, it reverts back to not working at srart. Any idea what might be happening? When I replaced the cable this weekend, I was certain to get the cable engaged in the transmission properly. I thought the cable might be too short or not installed properly, and was only engaging after it heated up and lengthened. But the same symptoms are happening with a new cable. Thanks in advance for any help you can offer.

Keith