6th Dec 2005, 20:59

You can go to your cadillac dealership they should be able to put a resistor in the ignition and the problem will be no more. That's what I did cost about 100 Canadian.

24th Feb 2006, 23:42

I'm a third generation owner of my Papa's 1989 Cadillac Seville and love it more than any new car on the market today. The vehicle has never broken down, is in beautiful shape, and has only 70k miles. There is one issue however, and that is I had to get a new paint job because the Arizona sun is hard on cars. She also has the front wheel drive 4.5L V8 engine.

9th Aug 2006, 00:40

Measure the resistance of the "chip" in the ignition key, and buy a resistor to match. They're available for less than a dollar at the local electronics supply outlet. The anti theft ignition circuit is the pair of thin orange wires coming out of the steering column, disconnect this small harness at the small black connector and jump the circuit with the matching resistor to the key.

Also, the 4.5 engine is not the 'Northstar'. See Wikipedia for the history of Cadillac engines.

1st Feb 2007, 15:26

Update to Sept 14, 2005.

I've now put 20,000 miles on the 1989 Seville STS, currently the car has 98,000 miles. The engine and transmission are flawless. The car is a high emitter though and the State of California required it to be inspected at a test only station again this year (2007). It passed the California smog test just barely, again. The fan control module failed last July. I temporarily wired the fans directly to the battery with a ground switch inside the car. I grabbed the first ’89 Seville/Eldorado fan control module I found at a junkyard a few months ago, installed it and it works fine. I pulled a Seville STS steering column (the Eldorado/Seville columns are identical, but the STS has a unique color) out of junk yard STS. The price was $40 at the counter and I elected not to buy it, the stiff wire push pull system I rigged up works fine, still.

The ABS is giving problems and there are multiple symptoms. The brakes cannot be relied on to stop the car in a hurry and the Teves system is a $950/$1,000 part not including labor to replace, it is not repairable. I am considering replacing the ABS with a conventional master cylinder and power booster from a similar E body car. Unrelated to the ABS unit problems, one or more of the brake rotors have recently warped, the brake pedal pulses severely. I hit a pothole and bent a rim; though not the fault of the car itself the car shakes at most speeds because of this.

The front tires were replaced and are wearing evenly and moderately so I was mistaken about an alignment issue. The right rear tire was severely cupped when the car was purchased indicating a failing shock. Now that tire has worn down smooth. I’ve been told that the shocks and struts should be replaced at 100,000 miles anyway.

I junk yarded a replacement radio, the cassette does not work on the replacement and will not accept a CD player adapter either, but the radio sounds beautiful. I bought a second junk yard radio in the hope that that cassette player would work, that radio was completely dead. One day the power antennae would not stop cycling, my ’87 Eldorado had the exact same problem. I disconnected the power and just pull the antennae up manually and leave it up unless going through an automatic car wash. The interior courtesy lights and the lighted door lock no longer work. The side molding fell off the right fender and the side molding broke on the left rear door. The finish on the elm burl wood trim on the doors is beginning to crack, I believe this is due to sun exposure. The rest of the interior is very good, headliner, seat and door panel leather carpets, dash etc.

2nd Nov 2007, 09:58

In 1989, the security system for the Deville was a dealer add-on. I am having problems with my security system, and I want to remove it completely, but I need a wiring diagram for the System VSS-300 Remote Control Security unit which was the dealer add-on.

11th Feb 2008, 23:05

My 1989 Cadillac Seville keeps having ignition problems every 3 to 5 years, and activating my theft system so the car will not start. We end up towing the car to the dealership as they charge us $404.00 in order to fix a problem that I feel Cadillac should recall and fix. Cadillac must know they have this problem with there cars, why are they refusing to fix it? I will Never Buy another Cadillac and will forever tell people they are junk.

15th Oct 2008, 15:29

I own a 89 Deville, and yes I have too replaced the ignition switch in it. I got an aftermarket one at an Autozone for $10.00, and it's worked fine for over a year now.

I keep going through radios in the car. I think I am on my fifth one. Now the amps in the radio keep going out, and it sounds like a speaker is blown.

The car has been in my family since it was new and it still runs like a dream. It's been "totaled" twice but is very easy to fix. Take it from me, a kid in high school.

15th Dec 2008, 18:58

Hello... I would just like to say that I came to own an '89 Seville, with the 4.5. 154,000 on it, it now (3 years later) has 170,000.

I change the oil every 40% (with oil 10-30 not synthetic). I've not had ignition switch problems. I did replace the trany at 160k and water pump.

The motor runs great. My father-in-law says "it's like riding around on my living room couch".

The stereo may have been like wow in its day, but that may change with some new speakers. I live in New England and the caddy doesn't mind the snow. I wouldn't trade it for anything.

3rd Feb 2009, 13:35

I mounted a new lock cylinder under the dash and used the old chip key in it. Just plug it in where the old one plugs in. You will need a key that fits the old cylinder that will no longer require chip. My 89 has 78000 miles and has had 3 ign. cylinders replaced before I purchased car. The anti theft system still works when I remove the key from the new lock cylinder. Problem solved! Other than that, this is an excellent automobile.

29th Mar 2009, 08:29

I have an 89 Deville with 115,000 miles on it for the past 5 years. Apart from a noisy water pump, which I am about to change, it's the best car I ever owned. I am 67 years of age and have owned lots of cars in my lifetime. This car is the most comfortable trouble free motoring car I have ever experienced.

I have it serviced every 3000 miles :- ie oil and fliter. I once accidentally locked the keys in the ignition and had to have a locksmith get into the car. He replaced the ignition barrel and new key at that time. At a later date I had a short on the trunk release barrel, which used to short out the battery so I removed the barrel. Now I unlock the trunk from inside the glove compartment only.

23rd Nov 2009, 08:14

I have a 1989 Seville. I had the same problem with the anti theft. An easy fix is to cut the orange wire coming down from the steering column, MAKE SURE IT'S NOT FOR THE AIR BAG!! This orange wire will have 2 wires inside, check the resistance in the key, either with a digital meter set to ohms, or take the key to auto zone where they can check it, one lead on one side and the other on the other. Then buy a resistor that is ONLY + or minus 2% the resistance of the key. It has to be in those specs or it won't work. Then just splice the resistor to the wires... the upper wires leading to ignition... no problems since for me...

6th Nov 2010, 22:04

Have an '89 Cadillac Seville, and the brakes have gone hard. Just put new brake pads in; a day later the pedal went hard. Do I need a new brake ABS unit, or can I change it? Help please.

16th Jan 2011, 22:36

My daughter has a 1998 Seville, and the trunk is stuck. I hear the click, but cannot get the trunk open. How do you open the trunk when the key and remote will not? I have checked the valet switch and it is OK. I tried taking the rear seat out, but cannot figure how to open it.