Have some weird things going on. Need help.

[lexxxxxxxx]

I have an 02 Aurora, 4.0, V8.
Few months ago I took my husband to work, came home and tried leaving a few hours later and it wouldn’t start (no crank, no start) I couldn’t figure out what was wrong that day (had the battery checked & replaced TWICE and tried to jump start it) so a week later we got my alternator checked, that was bad so I replaced it. still nothing. I had it towed to the closest shop, they had it for a month and couldn’t figure out what was wrong with it. I’m at my wits end.

Everything’s it’s doing.
-no crank no start.
-battery dies if plugged in.
-fuses were popping under back seat and hood.
-theft system fault pops up.
-my fuel pump comes on and works but my gas gauge won’t do anything.
-security light stays solid and it usually just blinks.

HELP ME.

[AuroraGirlFromMars]

It sounds like your whole system is going nuts... I would look at an engine computer. Thats not something we can tell you without being able to diagnose. A scan tool could tell you much more than just symptoms. A lot of computers actually will set codes for themselves, basically detecting that somethings not right and its unreliable. Not sure about an aurora. Although, the theft system fault makes me think its more than just that. if you want to start simple, jumping power from battery to the starter should tell you if starter is fine. Then you said you have fuel pressure. Put a spark plug tester in line with spark plugs and try to start the car by jumping the starter with the key in the on position. If you have spark, you should have everything necessary for the car to start. if you don't get spark, it could be the theft system. Iirc, the ECM will control fuel but ignition is left to the ignition module and runs through the theft module. If theft is "detected" it wont let you get spark. Never hurts to try the other key, either. But with where the computer is... wouldnt hurt to unhook its connection, clean the terminals, then hook it up. Of course, unhook the battery.

[mrn65]

I would offer the possibility of a bad ground cable. I would say check the ground from the motor to car frame, & from motor back to battery.

[tigger]

Google how to perform a "parasitic battery draw test". You need to find what is draining your battery first.

Sounds like you have a short circuit somewhere in the theft deterrent system, just another guess...

[RCA1186]

I thought the theft system disabled the fuel injectors as well.

[quixote]

Your battery & fuses sound like a totally different problem, but my father had a 1997 Pontiac with the same type of chipped security module... The module failed, when the car was 2-3 years old. The car would do nothing nothing, except all the dash lights flashing, & security light staying on. (I can't recall if the power windows & locks worked.)

Other people here have a lot more knowledge about the systems, than me, so I'll let them say if the security module could be collateral damage from some other electrical fault.

I would check & clean your ground connections to the body, however.

I found the weld holding the bolt the alternator grounds to, in my aurora, was broken & loose. I added grounds to both strut towers. (The driver's side one is just to a random spot on the block.) My car is a classic (5 years older than yours), and the only previous indication of electrical problem I'd had was a slowly draining battery. (This work did not fix the battery draining.) I had just read/seen in several places, that cleaning and adding grounds was a good idea in any car over 5 years old.

If you google "bad alternator," then go to 'advanced search,' and put "aurorah.proboards.com" in for the website, you should find a fair number of people discussing problems that they had with these cars and alternators. You may even find something closer to the problems you are having. It will take some reading/time.  I would also check for some of your symptoms, on youtube, including "northstar," and/or "cadillac," in your search.

These are really basic things, but sometimes even the experts miss or forget something.

[RCA1186]

Agreed, bad grounds to PCM could also cause a lot of problems, speaking from experience.

[AmunRoo]

Bad ignition switch?