I have a 2002 nissan sentra gxe 1.8l and i have had this car since 2007. when i bought the car it had 32000 miles on it. the has 55000 miles now and its giving me problems where the car starts hesitating and the speedometer starts acting weird. all the gauges go up and down and all the interior lights start to dim and my radio turns on and off on its own. i had the battery checked out and it was completey dead. i got a new one and it lasted me six days. i took it back and was told the battery needs to be charged. i also had the alternator tested and saw with my own eyes that is passed twice. i have no idea what else can be the problem. any suggestions would be greatful. i was reading a lot of complaints regarding this car and nissan wont fix it and they have no idea what it could be

link on relay
https://www.justanswer.com/nissan/2sn3q-2003-nissan-sentra-gxe-relays-the-hood-compressor-push-button.html
two fuse boxes link
https://www.youtube.com/watch?v=yIB4rlYwpjo
owners manual 03 sentra
https://justgivemethedamnmanual.com/nissan/2003-nissan-sentra-owners-manual/
Hope something here can help you

Part 1 -How to Test the Ignition COP Coils (Nissan 1.8L)

troubleshootmyvehicle.com > Nissan > 1.8L

Feb 12, 2013 - What Tools Do I Need to Test the COP Coils. ... coils (most commonly known as the COP ignition coils), on your 1.8L Nissan Sentra is pretty easy. ... When one COP ignition coil fails... that cylinder goes 'dead' due to a lack of Spark and is said to be misfiring. .... 2000, 2001, 2002, 2003, 2004, 2005, 2006 ...

Part 2 -How to Troubleshoot a No Start (Nissan 1.8L)

troubleshootmyvehicle.com > Nissan > 1.8L

Jan 17, 2013 - Checking for Spark With a Spark Tester. ... Your 1.8L Nissan will either have a distributor-type ignition system or the more modern COP ... A BAD fuel pumpwill cause your 1.8L Nissan Sentra to Crank but Not Start... since the ... Still, the other method that I've used to test for a lack of fuel... is spraying starting ...

2002 Sentra 1.8, no spark, code 0505... - Nissan Sentra Forum ...

www.b15sentra.net > ... > Technical Discussion

Nov 4, 2008 - 15 posts - ‎3 authors
I have never had a problem with the car before (02 Sentra 1.8/auto), so I had no need to post ... Originally Posted by Black B15 ... Join Date: Jun 2005 ... Can you see if the coilpacks are getting spark & work back from there? how many spark plugs do i need ? - Nissan Sentra ...
7 posts
Mar 19, 2010
Spark Plug Replacement - 2002 GXE 1.8L - Nissan ...
15 posts
Oct 12, 2009
1.8s starting problems - Nissan Sentra Forum - B15 ...
15 posts
Jun 23, 2009
No start on 1.8L 02 GXE - Nissan Sentra Forum - B15 ...
15 posts
Apr 11, 2009
More results from www.b15sentra.net

Have someone check the exhaust back pressure.

The 2002 Sentra's have a timing chain.

Here is a diagram of the 1.8 exhaust from the service manual, you can obtain a full factory service manual for relatively cheap from Promanuals.net here.

Every 10,000 miles partial service; change engine oil and filter, air and fuel filter's, spark plug's and check brakes fluid pipes and pad's. Every 50,000 full service. partial service plus change cambelt, check gear diff and power steering oils. Owners manual or any mechanic will let you know oil grades etc.

You will need a new catalytic convertor assembly. Yours is below treshold efficiency in other words its "no good".If you have it replaced, ask the garage/dealer to give you the old one back. Its worth some cash if its full. It doesn't matter thet it failed. They are going after the mesh inside of it and that is worth some $$$$. May not be much , but better than nothing.

SERVICE IT .....OIL PLUGS, AIR ,FUEL AND OIL FILTERS GET TROTTLE SENCOR AND THE MASS AIR FLOW SENCOR CHECKED

buy a used unit from the junk yard.

Check for vaccume leaks and also you PCV valve. check the hose too. Visually inspect every vaccume hose you can find. Sounds like a leak .