90GMC Suburban no speedometer & brake light on

[90GMCburban]

OK I know someone has to know, I have a 1990 GMC Suburban, parking brake light stays on, no speedometer, giving code 24 "vehicle speed sensor". I have replaced the sensor, the ABS control module, and the ECM, stil no result, took the instrument panel apart all looks good except single black wire coming from one of the panel lights not connectecd to anything, but that light works. Anyone have any idea what I am missing?

[GMMerlin]

Originally Posted by 90GMCburban

OK I know someone has to know, I have a 1990 GMC Suburban, parking brake light stays on, no speedometer, giving code 24 "vehicle speed sensor". I have replaced the sensor, the ABS control module, and the ECM, stil no result, took the instrument panel apart all looks good except single black wire coming from one of the panel lights not connectecd to anything, but that light works. Anyone have any idea what I am missing?

HAve you checked the wiring for an open

[90GMCburban]

Originally Posted by GMMerlin

HAve you checked the wiring for an open

I have checked al the wiring, replaced the speed sensor, the ABS control module, the ECM...everything seems perfect except for the voltage going to the instrument panel for the speedometer is fluctuating, but I have chased every related wire from end to end, no shorts, no blown fuses. the speedometer itself is fine, no explanation for the fluctuating voltage.