I’ve got a 2003 maxima se and it’s throwing the P0650 code along with P0462 & P1574. The P0462 is the fuel level sensor and the 1574 is for the cruise control signal malfunction. It’s the P0650 that has me in limp mode and scratching my head trying to find the short in my wires. As embarrassing as it is I will tell the story in hopes that someone can help me fix this problem.

I was checking voltage on the driver side power window lock and I had the wires on the volt meter connected in the wrong spot at the meter. When I probed the 2 wires that seem to go into the power window lock everything instantly got super hot. The car was running when this happened and after about 20-30 seconds I noticed the gauges stopped working. Tach, speedo, temp, & fuel were dead. About 10 seconds later the car started running rough. Not terrible but not smooth like it was. Then after a cpl mins it started acting like it was gonna die so I turned it off. I went to turn it back on and the battery was drained. I charged the battery up and drove it with no gauges the next morning. I made it about 12 miles before it died on me. So I charged the battery up again and drove the car back home.

The things I’ve done so far. Obviously charged the battery back up. Checked for codes and got the 3 mentioned. Checked all the fuses and relays, none were bad. Checked for parasitic drain. Good there. Checked voltage from battery as the car ran and the alternator is good. Until you rev it up and send it into limp mode then while it’s being reved it starts to drain the battery very slowly. Stop trying to rev it and it holds voltage. I’ve chased the wires from the window lock through the door and under the dash and it seems fine to me. I’m pretty sure it’s something to do with the the gauges not working that sends the 0650 code placing the car into limp mode. I just don’t know where else to look. I’m gonna let this thread cook and go check the gauge cluster harness now. I’ll revise this when I come back in if there is any new turn of events. If someone can help even put me on another line of thinking that would be amazing. I seem to be stuck where I’m at and really need my car. I don’t have extra money to just start throwing parts at it or I probably would at this point. Thanks for any help I can get.

 

as for the alternator, take your belt off and make sure the alternator pulley isn't loose. I've had the pulley loosen on me many times. I used RTV to glue the pulley to the alternator shaft and I've had no more issues. I've also had issues with the alternator plug slipping off and had to get a new alternator/compressor sub harness, 95-03 are the same...