I made the mistake of letting my younger brother borrow my 92 Auto and the first time I drove it after him I noticed two new problems:
1.) The speedometer does not function.
2.) OD does not engage.

I'm assuming that these two symptoms have a single cause. Has anyone else experienced this and found the solution?

Regards,
goyduf

 

Most likely cause is the VSS or Vehicle Speed Sensor on the either the tail housing of the trans or the transfer case, depending on 2 or 4 wheel drive. The PCM as simple as it might be needs a few inputs in order to engage OD, 1 is the vehicle speed.

It is either a bad sensor or the little square drive is stripped on it. Pretty much a 50/50 shot on either one being the cause.

 

^^^ agreed^^^^ tho hopefully it is somethign as simple as the wiring connector pulled loose....

 

Found that the distance sensor has a squared off post that was mostly rounded from wear. Waiting for the part to come in to see if that's the only problem. Thanks for the help.