Help! I have an '89 LX with 16's and the speedo hasn't been adjusted. What does that make my speedo read, higher than reality, or lower?
Also, my doors won't lock, manually or with the auto door lock button, any tips? from a very "green" point of view, things seem to be allright, but it-a no move-a!

 

Bigger circumference tires will make your speedo read lower than reality.The Tire Rack website has various tire diameter info available to compare your tire sizes.
I have never seen inside the doors of a Mustang to know how the locks work but on most cars there is a rod connecting the ***** to the lock mechanism.If this rod pulls out of the lock the doors won't lock.Sometimes the mechanism dries out and needs lubed to get the lock to work.WD-40 will work temporarily to see if that's the case.If that works use some graphite or lithium spray lube for a more permanent fix.

 

actually it was the actuators that were frozen. thanks.