Im gettin a transmission put back into my 04 nissan maxima, the original went out. The people fixing it have it installed but they are having problems gettin it from park to reverse. Any idea what could be goin on?

try putting it in drive first

The main ground wire brakes where it connects to the transmission. look under the battery carridge

Check your fluid level but if that is good you need to have the transmission checked. Not what anyone really wants to hear but you have a transmission problem that needs to be repaired.

There are two speed sensors one is called a revolution sensor that is located on the case of the transmission. You can take the driver side wheel off and see the sensor on the top of the case of the transmission. A 10mm bolt is holding it in. Easy fix

most likely you have a short in one of the bulb connectors or the hot wire from them is pinched on medal somewhere. Or you have water intrusion shorting one out. Inspect the bulbs. Leave both bulbs out. install fuse. Press brake pedal several times and hold. Inspect fuse. if its blown its the pedal switch that's bad or a pinched wire from there. If good put one bulb in. Test again,, then the next bulb. If you see something obvious fix it.

This is a circuit code. It could be the Transmission control module(TCM), the solenoid, or the wires in between. I would start by checking the wires running between the transmission control module and the transmission. Look for any obvious signs of chaffing or breakage. If the harness is ok, replace the solenoid pack in the transmission. If this still doesn't fix, replace the TCM.

throttle position sensor,or egr valve,also check your air filter,if this helps please gine me a fix ya vote

most likely you have a bad wheel bearing. It is very comen for a wheel bearing to go bad after an accident.