87 camaro iroc speedo cutting out

[mikieman98]

I have a 1987 camaro iroc-z with 305 tpi engine with 5 speed manual transmission. The other day had it out for drive on way home she started over heating she, just before hitting red line speedo cut out and stopped working, and check engine light came on. Stopped let her cool down awhile then drove her home but speedo still didn't work. Later that day when it had cooled down checked and replaced thermostat. Seemed to work ok. Let it sit for night and next morning checked out speedo cable and seemed to be okay, started it and drove it up and down road everything seemed to be fine until engine got hot then speedo cut out and engine light came back on. Can anyone help me with problem.