I put a transmission in my 2001 Mercury Sable Ls. The car runs beautiful but I have electrical problems. I lost all power to my wipers, all my doors, my radio and my trunk release. I have check fuses and everything. But if you jump the relay for the wipers they kick on? I have been trying for weeks to figure out what is wrong with my car and so far I have had no luck called multiple garages ford dealers nothing! So i'm really hoping you experts can help me out. And also my speedometer bounces around doesn't read accurate and sometimes falls past 120 then continues to bounce around I hear that was just a sensor. If you guys can help me out at all I would greatly appreaciate it. Thank you!

No one can diagnose any product over the phone or internet

You had to know, Dealers won't tell you anything

You have to go there,walk in the service bay from outside
& talk to a tech,who ever answered the phone, most likely
knows nothing about motor vehicles

You in my opinion, wasted your time so far

You need to get wiring diagrams, to use in order to
find & solve your issues

Sounds to me like you have a grounding problem, did the battery terminal cable on the negative side go to the tranny and the body of the car ? have you checked the relay to make sure it actually works? if you jumper it and that makes it work,, you probably have a faulty relay and if thats the case you may have had a power surge in that panel of fuses that shorted out some other things, have you tried testing each side of the fuse locations for power? the fuse may be fine but is there actual power at the source,, continuity tests on fuses for failure work fine if the fuse is \out,, check for an actual 12 volts with a meter, let me know what you find out,,