[Long]

No, I currently only have my CTS, had to sell my other car unfortunately so finding rides is quite difficult, but I believe the battery is fried from being attached to a system with a bad alternator that ended up blowing. So I'm trying to go get it load tested, but even with jumper cables attached to my Dad's CTS wagon I am unable to get any response, same thing jus engine light flickering and no turnover or anything. I will be going to load test the battery tomo tho and will keep yall updated. I figure if a fresh battery doesn't work then I'm going to try swapping my alternator with the one out of Dad's CTS wagon since our cars have the same motor and are same generation build.

Long, is there any chance you could forsee the alternator going out/blowing upon me accelerating pretty heavily could've sent a power surge to my ecm and ruined it? Lmk thank you!

- SharkBaitB00

To answer your last question: Doubtful.

 

[Lifespeed]

Long, is there any chance you could forsee the alternator going out/blowing upon me accelerating pretty heavily could've sent a power surge to my ecm and ruined it? Lmk thank you!

Never heard of this sort of failure mode, accelerating doesn't bother alternators or batteries. Water dripping down the A-pillar onto your BCM connector does, though. And corrosion remains after the water has evaporated. Still, the obvious first checks are battery and alternator, followed by BCM connector and other battery/alternator cable corrosion.

 

[SharkBaitBoo]

There are usually auto electric shops in decent-sized cities, I paid $130 to rebuild mine. Do you still have your original alternator?

The sunroof problem is the drain tubes, search it.

Damn I already returned the core to O'Reillys on Sunday. I'll go see if I can get it back, if not I'll just return their crappy branded one that's probably the issue in the first place, they charged me $300 for that pos!!! And the only reason I paid so much for that instead of a rebuilt Oem one online is so I could install it this weekend and not have to walk to my classes this whole week but here I am walking an hour to and from class today haha. I'll keep yall posted on what happens! Ty for the help and feedback

- SharkBaitB00

 

[silversport]

hopefully those that have had their alternator fail will chime in if I'm wrong with this but even rebuilt (because there are so many differences in what is actually rebuilt from one rebuilder to another) AC Delco alternators can fail...I believe it is recommended to get a new, Original Equipment Manufacturer AC Delco and not an AC Delco Gold or whatever they call their other alternators for a fix if it is indeed your alternator that is the cause of your grief...

Good luck with your CTS

Bill

 

[Long]

I would only trust a competent local electrical motor rebuild outfit if reusing the vehicles original alternator.

 

[Padgett]

Sorry, gave wrong impression. Am GM trained but retired and not a shop. Am fully occupied with my own toys. Just saying for an alternator, I'd rather buy a rebuild kit and DIY than pay a shop to learn, are rather simple inside.

 

[SharkBaitBoo]

Update : so installing the new (used but properly programmed and flashed) ecu did nothing, so I ordered an Oem (Denso) brand alternator and still with a fully charged battery same thing. Nothing, jus a flickering engine light and flashing traction control. Although last time I tried to start it I had the back seats down and noticed a loud rapid clicking coming from the trunk fuse box when I try to crank it, also a soft couple clicks from the fues box under the hood. I'm completely stumped and so is my Dad. Also I noticed a wire in the harness for the ecm has been previously cut and re krimpws together [ see image attached ] but the krimp is pretty tight and solid but very suspect as to why they cut that yellow wire previously. Also still getting same code.

If anyone here has any suggestions please let me know because my life is getting very hard to manage with no car to drive, it's been inoperable for 3 weeks now. So unless I can figure out the issue by Monday I'm going to schedule to drop it off next week at a diagnostic place or even the dealer, which we all know is going to be more of a headache and a fortune. Plus I don't like nobody touching my baby but me haha. So please any suggestions I'm willing to try.

Thank you so much for reading and helping.

- SharkBaitB00

 

[Lifespeed]

Electrical troubleshooting skills are rare amongst mechanics, including dealerships.

 

[SharkBaitBoo]

Electrical troubleshooting skills are rare amongst mechanics, including dealerships.

So what would your next action be if it was your car? I'm not gonna total it or scrap it over an electrical issue that started when the alternator blew, there has to be an answer. I've already put custom coilovers, rims, sound system. I wanna fix it and keep the project going but I'm stumped.

-SharkBaitB00

 

[SharkBaitBoo]

Electrical troubleshooting skills are rare amongst mechanics, including dealerships.

Does this sound like to you it could be a starter or bad solenoid with the starter? Lmk

-SharkBaitB00

 

[Lifespeed]

I did not claim to be able to diagnose your problem remotely. We're aware of some common failure modes on this forum, the alternator is notorious. Water corroding the BCM connector is another one. Starter issues aren't common, but always a possibility.
If electrical troubleshooting isn't your strength, and you don't have the service manual and schematics to refer to, you probably need to hire these skills.
PM me, I might be able to help with schematics.

 

[Lifespeed]

What does the battery voltage drop to when you try to start it?

 

[SharkBaitBoo]

What does the battery voltage drop to when you try to start it?

Schematics would be useful, especially the pin out for the ecm connectors. Btw I forgot to mention I did check the bcm under the steering wheel and everything appears to look fine w no corrosion, some rusting on the steering column but nothing serious, I know I have the leaking issue but this car has always lived 99% of its life in San Diego where rain in uncommon. The voltage if I remmebr correctly was dropping to about 12.1. But it definitely has a powerdrain because we had the battery connected and try to start it a few times and then left it w the key off for maybe ten minutes and the voltage was 11.4 or something. This is reading voltages straight off the battery posts in the trunk.

At this point would you look for an electrical diagnostic place or jus use the dealer? Personally?

-SharkBaitB00

 

[NorthernSRX]

@SharkBaitBoo - In the circumstances you've described, I would try to eliminate component failures. Have you tried to jump the starter relay? If the car will start when you jump the relay, I would zero in on investigating the ECM as the culprit. At least then you won't be tempted to throw a new starter or solenoid at the car.

FWIW.

 

[Long]

Also pop off the end of the dash on the passenger side (open front pass door, remove end cover).
See any corroded connections?

 

[SharkBaitBoo]

@SharkBaitBoo - In the circumstances you've described, I would try to eliminate component failures. Have you tried to jump the starter relay? If the car will start when you jump the relay, I would zero in on investigating the ECM as the culprit. At least then you won't be tempted to throw a new starter or solenoid at the car.

FWIW.

I already tried installing a new (used but properly flashed) ECM with absolutely no luck. Still jus get no sound and flickering engine light. How would I attempt jumping the starter relay?

-SharkBaitB00

 

[SharkBaitBoo]

Also pop off the end of the dash on the passenger side (open front pass door, remove end cover).
See any corroded connections?

The end of the passenger dash on the bottom? Can you be more specific and I will definitely check for corrosion and let yall know what I find. Probably will attach images of what I find.

Also, I did check the bcm under the steering wheel but I've heard is there possibly also a "rear bcm" located somewhere in the back I could check out?

-SharkBaitB00

EDIT: sorry for double posting, will try to break this habit now as I'm new here and see this as a possibly etiquette issue

 

[HurstGN]

You might want to look at the Scanner Danner you tube channel and watch some of his "car won't start" videos. Some of the basics he covers may be a good starting point to eliminate components that are not bad.

 

[NorthernSRX]

I already tried installing a new (used but properly flashed) ECM with absolutely no luck. Still jus get no sound and flickering engine light. How would I attempt jumping the starter relay?

-SharkBaitB00

The under-hood fuse box has a relay and a fuse for the starter:

I don't have the pattern for the contacts in the relay itself but this video gives you an idea of how you can jump the relay:

This guide is for a gen 1 CTS and I do not know if the contact pattern is the same for gen 2 starter relays.

 

[SharkBaitBoo]

You might want to look at the Scanner Danner you tube channel and watch some of his "car won't start" videos. Some of the basics he covers may be a good starting point to eliminate components that are not bad.

Well I've already eliminated the following: new alternator (which originally was the failing component, went out while I was accelerating pretty hard), new battery, new ecm (properly flashed to my vehicle), and all the relays and fuses in both fuse box appear to be working when I do a test with a voltmeter.

I'll try jumping the starter relay next n take a look under the passenger dash board and let yall know what I find in a couple days. Thanks for the consistent help from all the cadillac lovers here.

-SharkBaitB00