SLS dead


Asked by Jun 20, 2013 at 08:26 AM about the 1997 Cadillac Seville SLS FWD

Question type: Maintenance & Repair

I'm a genius.  I hit the sulfate button on my fancy charger while battery was still connected
to the car.  Did I blow a "master" fuse or fusible link?  When you get done laughing,
please help!

14 Answers

Sulfation, the number one cause of early battery failures, can be safely reversed, using high frequency electronic pulses. But it does not use high voltages. BUT, these high frequency pulses can play havoc on your ignition system, the parts that are 'hot at all times'. That feature on your charger is fine, it will bring an old battery back to life for a while, maybe a short while, but I have not seen what claims the manufacturer makes. But it will not turn a 5 year old battery in to a new one. Hopefully you DID blow a fuse, instead of these pulses going to your ECU. That may have fried it. Let me find a diagram of a '97 Seville and see what we can see. Meanwhile, back to the chalkboard for you to finish writing out W^5x 5/11 `|\^/; (x)y %(9W) formula there for you advanced physics class for your students.

1 people found this helpful.

Hey all in fun, okay? No offense. I looked at lots of images and the best I can find for a '97 Seville is this one. I see no "mega fuse" as it's called in some cars. My best suggestion is see if your ECU can be tested, the problem with that is it is non returnable if you buy one and that is not the problem. Who we need is tenspeed, he is a battery expert. Maybe he will see this.

3 people found this helpful.

click the image to see it and pull then pull and check the PCM fuse

4 people found this helpful.

PCM BAT caught my eye. Up to the light, it looked good. (Remember old axials would fail, but you might not see it?) Would a guy Ohm check a GMT fuse?

Well, ohm is a measure if resistance. So yes, you could use an ohm meter and if it shows no resistance then the fuse is good, Or you could use a continuity light or meter and find out that way also. Another option is just buy another fuse. But hold on ......Let's go back a bit. The car will not start, no power, no lights, nothing?

1 people found this helpful.

Right. Deader than snot on a doorknob. I am a BSEET and I did this! I should slam my head with my hood. Luckily I have an extra car. I keep weird hours, might go to bed soon. We'll be in touch. Maybe I can pop you some PayPal $ for beer or whatever if we get this figured out. Another fuse panel in the trunk. Hmmm, pretty far from the battery physically, anyways.

My pleasure to help, when and where I can. Although the hood may have a dent if you do that. PM me if necessary. And we WILL figure this out.

PS I don't want your money, but that is a very generous gesture. Thanks, but not necessary. I have on one occasion helped a woman save $4,000 that her mechanic wanted to sell her a new (well... rebuilt) engine that needed a new catalytic convertor that was plugged, but tempting as it was I get my karma and kismet from just helping

2 people found this helpful.

I relate to the Karma thing. I've helped friends with their cars and computers etc. Good karma to help elderly folks etc too.

1 people found this helpful.

I am on the same page with the Karma,what goes around comes around. Dave on the continuity test with a ohm meter, I think it should be the other way around, if you get a resistive reading then the fuse would be good.


0 Ohms is a good fuse. DeVry Phoenix Class of 1984. Some people laugh, I've done ok. I just pulled the dunce move with my car LOL!


where is the pcm on the 2002 Seville sls?

3 people found this helpful.

If my computer ain't reading in 96 SLS Seville can it be a fuse

Same issue here: 1995 Cadillac Seville SLS VIN = 1G6KS52Y8SU827391 Mom and Dad snowbirded this year in FL, left car in unheated garage back in deep-freeze Ohio, they returned in early Jan, I went over to see them, Caddy battery low, not quite cranking over, went out and bought them a $29 plug-it-in-and-walk-away charger gizmo from big box store, did just that to Caddy, came back 24 hrs later and car fired up first time. Sweet, Life is Good! ....but then couldn't get shifter out of park for some reason. Brake pedal to he floor, jiggle steering wheel, jiggle shifter handle, jiggle everything in all possible combinations, nothin doin. Car sitting there idling happily, can't get damn thing out of park. Shut off car, return home, hit the Caddy websites, read up on the issue. Learn that apparently the way the car gets the signal that the brake pedal is engaged (which is necessary to let you shift out of P) isn't actually the pedal, it's whether or not the brake lights are lit. (or maybe more precisely, whether or not the brake light circuit is closed, irrespective of whether or not the bulbs are actually emitting light? not sure if equivalent, i'm not an EE like everybody else in here :) Armed with new knowledge, dutifully trudge back to Mom and Dad's next day, go to turn key in ignition, aaaand....nothing. Not low battery, just nothing. Which typically means not a battery issue but an electrical one. Crap. Go back to the 'nets, google up elec issues in old Caddies, learn about "battery fuse" (?), trunk fuses etc...but also stumble across this page here, which expands the possibilities to the bad-case scenario that i've fried the ECU with the battery charger due to the old battery and the "sulfation" issue per DavidH25's comment. Ack, hope not. So, a few questions for everybody: Q1: What amp fuses should I have in my pocket for next time I go over there to putz around on Dad's caddy? I'm guessing I'd need new replacements for both (a) the "battery fuse" (wherever that one is), and also maybe for the brakelight circuit fuse? in the trunk i assume? if that one's blown, that would im guessing account for the locked-in-Park situation with the shifter. Q2: What's up with this battery fuse? Where is it located? Can I get to it without too much fuss? Is this one of those absurd dealer service dept sweetheart deals where the designers locate the fuse so far inside that you pracically have to pull the engine to get to it? Q3: Re the shifter issue, if it's not the brake light circuit like I'm guessing, then what circuit IS feeding signal to tell car to release out of Park, and how to I resolve THAT issue? Thanks in advance for any help/advice/shoulder to cry on, you guys are a credit to apple tree Radio Shacking DIYers everwhere imho :)

Your Answer:


Looking for a Used Seville in your area?

CarGurus has 252 nationwide Seville listings starting at $1,495.


Cadillac Seville Experts

  • #1
    Tom Demyan
  • #2
  • #3
View All

Related Models For Sale

Used Cadillac DeVille
1,280 listings starting at $1,150
Used Cadillac Eldorado
286 listings starting at $2,995
Used Chevrolet Impala
442 Great Deals out of 25,964 listings starting at $950
Used Chevrolet Camaro
238 Great Deals out of 27,434 listings starting at $2,077
Used Chevrolet Corvette
88 Great Deals out of 15,086 listings starting at $3,620
Used Lincoln Town Car
28 Great Deals out of 1,468 listings starting at $1,900
Used Ford Mustang
268 Great Deals out of 38,445 listings starting at $1,350
Used BMW 7 Series
107 Great Deals out of 4,862 listings starting at $2,399

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.