Trans was rebuilt everything working then overdrive and cruise quit. Trans tech says it will engage at Trans but signal not coming from ecu. Currently speedO is off 10mph at 60mph. Tach says its idling at 500 but the engine seems higher, occasional tach bounce. At one point before overdrive quit a guy working on it put a different 125mph cluster (mine was a 125mph to start with) with one from another dakota. Was wondering if there was a different in the Tach or speedO from either a v6, manual trans or just a later model that would cause the overdrive issue. Where to get an original correct cluster or a solid plan to troubleshoot the overdrive issue.
Thanks
Kevin

PCM controls O/D. Needs to know what speed you are going though, if it doesn't, O/D will never engage. (even though the first three will shift just fine.)

Getting any codes?

I have no check engine light on. Not sure how to check codes on a 91 dodge dakota. I know later model vehicles have an obd port. What do I need?

An ignition key.

With the engine OFF, turn it ON, OFF, ON, OFF and ON within 5 seconds (note: DO NOT START! Just turn it on).

Watch the CHK ENG or PWR LOSS light.

Count the blinks.

You'll have blinks with a short pause, then a medium pause, another set of blinks, then a long pause.

You'll end up with a 55 code (END OF CODES).

Toss that at Google with "OBD CODES 1991 DAKOTA" or whatever year it is.

RwP