Question-------------------------
Followup To
Question - Ted, there is no cable, there are some electronics at the tail shaft. The engine light does not appear. Could it be in the head? Also,
why would the speedometer work in the afternoons when the tepmerature is high? The only reason I can think of to work only late in the day but never in the morning. Is the function dependent on vaccuum, fluid levels in the transmission, etc ?
Answer -
I'm not sure if it has a speedo cable or a speed sensor, I tend to think it has a cable, check to see if a cable goes through the firewall inside to the speedo, if not there is a speed sensor mounted on the tailshaft on the transmission. If the speed sensor goes bad it should turn the check engine light on.
AnswerThe speed sonsor on the transmission is basically an on-off
switching device, it is magnetic and a reluctor wheel passes by it to make or break the magnetic field, the computer sees this as a digital signal, it's converted back to an analog signal to make the speedo move, the reason it is temperature sensitive tells me that the problem may be with an electronic component, I would suspect the speedo head itself as the cause.
