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Seville STS 1993 Acts like its in ACCESSORY after KEY OFF


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I wonder if he really means 'circuit breaker 1 + 3'. I was hoping he would've of chimed in. 

I don't see any ignition relays in my '93 service manual. 

The underhood fuse block can develop moderate corrosion issues. 

I would still check the ignition switch and wiring. Techs like to hack into the harness at the switch. If you remove the lower dash panel you should be able to see if anything looks suspicious.  

 

breaker1+3.jpg

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And....a pic. This is a 1987 Chevy truck column. But you can see the white switch mounted to the column near the top of the pic (not key part area).

The GM Saginaw columns were made for 30 years.....all pretty much the same.  

87chevycolumn.jpg

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  • 9 months later...

Gentlemen, long time no see.

Update: I now have the 1993 FSM and it has helped significately however I am still somewhat at a loss.

Battery has been replaced, Alternator has been replaced(twice), Starter has been replaced.
G100 has been cleaned.  Alternator terminal has been rebuilt.  Found massive corrosion all arround and replaced entire power line, and checking each ground as I go.

Current issue: When I backprobe ECM I have +12 on the Generator to L terminal line before Key on.
Alternator does not seem to be turning on, but I am also not losing voltage as quickly as I would expect.

Codes before Turning car on:
P023
P052
P109
I052
A048
T071 - Current
S011
S061
S021
S026
S021
S036
S037 -Current
S038
S044
S061
S062


While running:
P023 - Current
T071 - Current
S037 - became History.

I rev the engine and hold it 1500-2000, I don't see a gain or a drop.
I let it idle and it stays consistent ~11.7-11.9V.
At idle it does not dim lights but it does report that I goes down to 11.2ish with AC fans, radio, brights on.
It does not give me the Battery No charge message, or any real obvious indication of it losing power other than it not starting in a voltage range I am familar with.

Battery does seem to be losing voltage but very slowly.  There no longer appears to be any parasitic draw as well.

 

 

I did have 13-14V output earlier this week, before an incident where the new power line was too tight up against alternator,  causing it to be sliced in half during operation.

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Check the ground wire from the battery to the engine for signs of corrosion under the insulation.  I worked on a 95 that had a badly corroded ground wire and I believe it triggered codes.  If the corrosion is bad enough, it will increase the resistance in the wire.  See this photo

If this is a "lifetime" alternator from an autoparts store that may be your problem.   Use ONLY an AC DELCO rebuild, or a rebuild from a reputable builder or a new AC DELCO, these cars are picky when it comes to alternators. It has to do with the regulator if I recall.  Use AC Delco reman/rebuild. 

DSCN9967B_zpsxqyohl1c.JPG

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

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Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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check the red wire on the alternator, they were prone to breaking. The wire will feed into a bulk connector on the lf framerail underneath the darth vadar black plastic cover.

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That wire indeed had broken.  I spliced it back together at the connector.  If this wire was broken in another spot would that cause the line to have voltage before key on?

FSM says key off the line should be 0v.  currently its 12v key off.

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Have 

9 hours ago, productionx said:

I did have 13-14V output earlier this week, before an incident where the new power line was too tight up against alternator,  causing it to be sliced in half during operation.

It is possible you damaged the diode bridge or regulator, if it grounded

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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1 minute ago, productionx said:

That wire indeed had broken.  I spliced it back together at the connector.  If this wire was broken in another spot would that cause the line to have voltage before key on?

FSM says key off the line should be 0v.  currently its 12v key off.

How did you splice?  Twist, solder, shrink wrap, tape.  Simple twisting is not sufficient.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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2 hours ago, productionx said:

twist+tape+heat.

voltage is same at the plug as it is as the ecm.

Be sure that it is a good really good connection, when a load is placed on it the joint may be compromised.  Have you checked the output of the alternator with a voltmeter?

Do the headlights flicker?

Is the voltage steady or ranging up and down?

It is odd that you had good charging until the wire being damaged.  Did the wire ground out?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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4 hours ago, productionx said:

No headlight flicker,

Seems steady

Did not ground out, the turning bit sliced the cable.  ran it to safe place and immediately disconnected battery to examine.

Do you have a voltmeter?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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If you had good charging before the wire issue it must be related to the wire.

You are down about 1 volt.  

You are using an ac delco alternator

I trust that the wire that was damaged is the wire from the battery correct?  That is the output terminal from the alternator. 

Connect a voltmeter to the output terminal of the alternator. Turn all loads off ie, AC, hvac, radio, etc.  Run engine st 2500 rpm for 30 seconds, is the voltage 14+ volts?  Yes or No?

That is cold engine temp voltage of 14 to 16, at operating temp 13 to 15 volts.  If not, replace the alternator.  

^^^^^^ that is the functional check from the FSM.  

BEFORE I replaced the battery, I would solder that wire. 

Has the alternator been replaced SINCE the wire was damaged?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The answer is No I am not getting 14V.  I will disconnect alternator tommorow and backprobe that pin again.  I suspect the alternator is not at fault here.

I suspect i messed up the L terminal wire from the ECM while testing(probably broke it somewhere).  FSM shows me generally how that wire is routed unto a point.  i can only physically trace the bundle to about somewhere over the oilpan.  Any idea where in the firewall that mass of wire comes out?

 

I can pull the alternator and throw another one in, but i just pulled an alternator that was working a couple weeks back that i do not suspect failed and was related to this L terminal wire having the wrong voltage.  Diode test shows it is pushing energy the correct way and not flowing in the reverse.

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Occasionally problems become to convoluted to diagnose in a forum like this.  This is a give and take of info and we dont seem to be too successful at that.  I need to back away at this point, I have not seen a problem like this before maybe someone else will pop in and give help.  

I dont think I have quit on a problem here since 1995, this is the first you seem to have all the answers

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I definitely don't have all the answers and do appreciate the step through, it is important to troubleshoot from the bottom up despite what probably seems like annoyance on my side.  I have about 300 notes written and 100 tabs for markers on the Factory Service Manuals, along with notes from this forum and caddyforums and all data.

 

I am going to undo battery and alternator cables, check battery ground wire again, and i am considering running a line directly from ECM 2c14(red wire) to L term as a test.

 

Ran car last night to grocery store after charging battery for 2 hours bringing battery to 12.9 according to multimeter.

Car showed 12.2 while off on dash, 12 on first start, then it was a slow bounce down to 11.5, but definitely not as fast as if there was 0 alternator output,

I also need to backprobe that ECM pin without alternator connected to see if anything changes.  Thank you for your advice, and if anything else comes to mind even seemingly unrelated i am willing to go check it.

 

Also, if i determine that wire is somehow at fault, where is my best point through the firewall?

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I think you are possibly making more out of this than you need to. 

The first thing I would do is have the alternator tested, but a shop that can do it competently.  You need a good starting point.  Assuming you have a good alternator can get you into trouble.   Either have it tested or install a KNOWN GOOD (this is a term that is used forever) alternator.  You need a solid starting point.

You could be on a wild goose chase and the alternator crapped out on you, remember its new, it could have a problem

Also, I NEVER EVER back probe any circuit with a PCM because you can damage the sensitive circuits.  I follow the diagnostic trees in the FSM

Also, If you had a L or F problem with the alternator you WOULD get a code.   Any codes for alternator?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I came to this late. 

I am not exactly sure what the issue is that you are having. Is it that the alternator is not charging?

What wire got sliced and how did it get sliced? If it got sliced I am going to assume that whatever sliced it grounded it out.

What wire are you probing at the alternator that is showing voltage when it is supposed to be 0?

I want to stress that I have replaced the alternator regulator pigtail enough times because one of the wires corroded or broke internally either right at the plug or within a few inches from it.

I have mistakingly replaced a few alternators because of that pigtail.

I also do not recommend under any condition backprobing pins to the ecm while it is plugged in. May have undesired results

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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First off I am going to show you my current reference point of information.  Then I will respond to both of the questions you posted.

https://imgur.com/a/joVwtBa

Here is an image gallery i uploaded based upon this.  Its been raining all day so testing was not an option.

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to BodybyFisher

"I think you are possibly making more out of this than you need to. 

The first thing I would do is have the alternator tested, but a shop that can do it competently.  You need a good starting point.  Assuming you have a good alternator can get you into trouble.   Either have it tested or install a KNOWN GOOD (this is a term that is used forever) alternator.  You need a solid starting point. 

You could be on a wild goose chase and the alternator crapped out on you, remember its new, it could have a problem"

 

Completely valid, idea, There is an Oreilly, Autozone, and Advanced in reachable distance, and i suspect the only one that has a chance of not doing it wrong is Autozone.

 

"Also, I NEVER EVER back probe any circuit with a PCM because you can damage the sensitive circuits."

I was very careful with this, and did see the potential for frying it, consider it a stupid desperate question of what the module had on its side.

No alternator codes, No messages on Dash

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to rockfangd

"Is it that the alternator is not charging?"- Correct

"What wire got sliced and how did it get sliced?"- Battery to accesory terminal was the side that got chopped up by the [wrong word] flywheel? part of the alternator, where it has the little fins just before the belt goes onto the [wrong word] spindle?

"If it got sliced I am going to assume that whatever sliced it grounded it out." - This could be but did not completely cut through it was about 80% and the wire did not graze up against the alternator housing.

"What wire are you probing at the alternator that is showing voltage when it is supposed to be 0?" L-Terminal

"I want to stress that I have replaced the alternator regulator pigtail enough times because one of the wires corroded or broke internally either right at the plug or within a few inches from it." - This DEFINITELY did happen which is what lead me to believe the previous alternator failed!  I admittedly was not very gentle when I was trying to physically move my hand along where the line was going, and so i would like to run a new line after i get my next chance to test.  Would it be safe to go directly from ecm redwire pin into the lterminal connector pin if i be very careful and have battery disconnected while installing said test line?

I have mistakingly replaced a few alternators because of that pigtail.

"I also do not recommend under any condition backprobing pins to the ecm while it is plugged in. May have undesired results" - Wont do this again

 

You guys are awesome, thank you for your continued thought process on this fiasco.

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