cobra420

I put a new factory clutch in a 98 cobra mustang professionally installed. it was discovered that speedometer is sporadic, and found strange black box wired into the speedometer. and under the dash. This problem ahs the professional transmission man not knowing what this object is or how to fix this. Any help and or advice is greatly appreciated

dawson1112

That box is almost certainly a Dallas mustang speed calibration box. And its used to calibrate the speed signal on t45 and other transmissions , when other than factory tires are used, rear gears are changed and the transmission does not use a speedo gear but instead a magnetic pick up to read speed. Or the transmission has been updated to a newer trans and the signal needs to be converted either from digital to analog or visa versa.

Undo the vehicles negative battery and wait about 30 seconds, then hook it back up. Those boxes are usually tied to the cigarette lighter and sometimes need to be reset by disconnecting power to them momentarily.