You are here:

Cadillac Repair/95 STS Electrical Issues

Advertisement

Expert: - 7/26/2011


Question
Hi Rob,

There is obviously something I wrote wrong.... your comment"I don't understand where you came up with my contempt for the 1995 Northstar, but while you mention it, I have contempt for engineers that designed the Northstar and all other aluminum engines without a warning that they self destruct from over heating....." was not intended at all.  You don't know how much I appreciate your help.  You can also see the positive feedback I gave you.

Back to the issue at hand the alternator is controlled differently in the 4.9 and 4.6....  The 4.6 is controlled by the PCM.  Today I was able to put a volt meter on the PCM circuit to the "L" terminal of the alternator.  Key off, the usual 0V, however, engine running it was only 3-4V when it should be Battery voltage....  This has lead me to believe there is an issue with the PCM (a rebuilt GM PCM installed about 2002).  Took a PCM out of a salvage 95 SLS, plugged it in my STS and the "L" terminal voltage at the PCM connector was 11.9V and now my IP DVM was reading 13.6V.

I am fortunate with my 95 in that I only had one time when the coolant level started to get hot.  The water pump idler pulley bearing failed and lost the belt..... I stopped immediately.....

Thanks again for your help and excellent answers to the many posts here.

Answer
Hello,

You are more than welcome, but keeping up with these year changes want my mind to explode!

GM didn't used to pull that crap. Everything in the charging was pretty much the same, unlike Fords where o order a tie rod one practically needed the color of the car. That is why I stayed with GM so long. Any vehicle is good as long as it's functioning.
Glad it worked out and thanks for getting back to me on the fix.

http://www.autotheftexpert.com  

Cadillac Repair

All Answers

Answers by Expert:

Ask Experts

Volunteer

Rob Painter

Expertise

Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?

Experience

Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

©2012 About.com, a part of The New York Times Company. All rights reserved.