1986 GT 2.8V6 Automatic 62K miles.

I've only had this car for a few weeks. It is a low mileage and very original car. I was out on the interstate last night and had to brake really hard for a traffic jam at my exit. When I did that, my SES light came on and my speedometer and odometer quit working. I stopped to see my mom then drove home. I tried to use the cruise control which had worked a few days earlier. Now it does not work. That indicates to me that it isn't an ECM problem. It seems like a problem between the VSS and the speedo. Thoughts?

The radio and everything else works correctly. The car starts and idles and drives normally. I checked the fuses. All are good. I removed the gage cluster belly pan and disconnected and re-connected the speedometer wiring. No change. I inspected the VSS and the connector seems tight. It was still in place and the clip is not broken. The wire loom from the alternator and VSS do seem to be riding low and may be in contact with the axle. I could see or feel no damage to the plastic sheath.

I only had the one code. Code 24. I have spares so do I need to start swapping parts or does this appear to be a wiring problem?

Thanks,

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Jonathan
23K mile '85 notchie - Still under construction
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Was the car on cruise control when you hit the brakes?

No.

Yes, no is not an ECM problem.
VSS to the speedo driver then to the ECM etc.
A dead speedo board or VSS is likely.

The speedo gets that the power from the radio fuse. For ground it goes to G201 G202 and G504, same thing is everything.

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I guess the next thing I'll try is a VSS swap. Is it rare for these units to go bad other than the gears wearing out?

Jonathan