Drove car to lunch shut it down when we returned to car it would turn over but not start.I towed it home look at all obvious connections to see if anything loose the proceeded to hook up a computer scanner and the scanner read unable to connect. so I located the computer located bahind the battery and it was barely touchable it was so hot. My question what possible causes or things I should check before I connect a new computer to this system. Thank you Walt

What have you replaced recently? One man in UK replaced a relay unit in the igniton wiring with one that fit and worked perfectly for 11 minutes and 46 seconds exactly, then all power in the engine was lost. Turn the key to off, turn on, start engine, perfect for another 11 minutes and 46 seconds, ad infinitum.he drove 1100 miles including motorways with this fault, on, off, on, off....
At home he found that the relay that fitted perfectly was the type of relay for the rear window Heater on a French brand of car..the one which turns off after 11 minutes and 46 seconds.
it's a long shot but did you?........
Please get back to us with the solution as it may help someone in the future.......

you have problem with the alternator

I have a customer with a 2000 Nissan Xterra 3.3 liter V6 with 180k miles. He stated that while driving on the highway the vehicle is fine. Once he exits the highway and drove on surface streets the engine stumbles, sputters and shuts down when he stops. The fuel pump is located under the right side rear seat. I removed the inspection cover to view the electrical connections. No problem there. I drove the vehicle for approx 20 minutes and it hesitated a little but not enough for me to come to a good conclusion. I needed the engine to heat up some more so I drove to Panda Express for lunch. I got my lunch to go, return to the vehicle and started the engine to eat while the engine idled. After my lunch was over I drove back to my customer's house. On the way God bless me with what I was searching for...the engine started to sputter. To shorten this story I replaced the distributor with a brand new assembly from AutoZone($233.65). Once I removed the factory distributor I spun it by hand and that's when I could feel that bearings were rough & worn.
Problem solved and my customer is happy.

which fan are you talking about cooling Fan for Radiator or Blower Motor Fan for heat/AC

Take it back to where you got it and make them refund your purchase price. If they refuse and you finianced it go to them, There a law called "The Lemon Law" that makes it unlawful to sell something like that. Sounds like you sure bought one. Don't do anything to it just get hold of the place where you bought it and tell them to come get their junk out of your yard! dhgill1949

Check the batteries, you can have one bad cell and it will pull down the voltage from the other ones killing both over time

Sounds like you have a bad glow plug relay that could cause a power spike and drain your battery,it could also take away power to the fuel pump causing the loss of power.Hope this helps you out some!!

the glow plugs probably need replacing, it seems they are not heating up the gas enough.

Confirm the condition of your battery then check the ignition switch and power distribution box for any loose connections

Welcome to fixya

this could be cause by the thermastate or the fan could not be working i would replace the thermastate and check fan make sure it is running when the car heats up