27th Feb 2003, 12:58

Because of all the electrical accessories in these cars, there is a parasitic drain on the battery at all times. Leaving one sitting for a week can cause a dead battery. Think of all the things on the car just waiting for input -- the anti-theft system, stereo, ignition, locks, illuminated entry, etc. etc. You may not actually have a problem to fix, beyond the fact that you aren't driving it enough to keep the battery alive. Try installing a battery cut-off switch and see if that doesn't make a difference.

8th Mar 2003, 05:22

I have a 1989 Cad. Eldorado Biarritz. It is a great car. 267,000 miles orig. engine transmission, etc. The power drain has never been a problem with mine, but sounds like a glove box light, the trunk light, OR the under hood service light could be staying on "undetected". I would advise removing all three bulbs and see if it starts after a week. if so, replace one bulb at a time, seeing which bulb, when replaced, causes the battery drain. If this doesn't work, then I'd reccomend shutting off the car (all light's & accessories), and sitting in it for 15-20 minutes listening for any noises whatsoever. Sometimes you will actually hear (or see) the cause of a power drain! Examples of this would be to see a light/display come on somewhere, or hear the automatic power anteana, or "easy close" power trunk malfunctioning. Sometimes a small "clicking" noise (electric arc.) will be heard thus isolating the problem. A final suggestion would be to immediately disconnect the battery after shutting off the car, Let the car set a week, then reconnect the battery and see if it starts. If it won't start at this point, the battery is not well suited to the vehicle... no matter how many times it has been replaced!

29th Mar 2003, 13:32

Hi! I have an 85 Eldorado that my neighbor gave to me. The dealer only offered her 600.00 for their car (always garaged, 32,000 original miles and overall very mint) as a trade in so in her annoyed state, she parked it in my driveway knowing I had admired it for years. State inspection required my purchase of a wiper blade. However after taking ownership, I replaced the dead battery after the first few weeks figuring it had been in there for a long time, but the new one went down also after a few weeks. I removed the tail lights to polish the lenses and nights later before the new bulbs were installed, I discovered a faint light coming from inside the trunk. I think the socket for the trunk light is a mercury switch maybe so I repositioned it and that solved everything. This cars sits (in the garage) for up to a month at a time depending on weather and my schedule so little electrical leaks would be noticed, but so far in two years, the battery stays right on top of things. After finding this, I checked the glove box too, but all is well. This caddy is a survivor!

18th Nov 2003, 16:50

Disconnect the ground terminal and go "circuit probing" with a 12v test light. Anything drawing power will illuminate the light. You could also pull fuses for certain circuits one at a time to help isolate the branch.

21st Mar 2004, 15:45

I've owned two thus far, and my 1984 Eldorado really had little in the way of battery problems like you have, it did flood occasionally though and I'd have to unplug the injectors when starting... annoying. For my drain problem ('88 Deville I have now), I found the fans for cooling the radiator didn't shut off automatically, but it only happened once, hard not to notice as they aren't quiet... also found the bulb under hood is broken at the base and slightly rusted in, I'll still have to deal with that and getting a new alternator, but good advice from readers here. Cadillac ownership expects the customers to pay for service without getting questioning cost, but they aren't really on a par with Mercedes and Rolls sad to say, so weekend mechanics who love the Caddy's are good to see.

23rd Apr 2004, 10:53

I have a 1986 Eldorado and experienced the same slow battery drain. I completely unhooked my stereo, thinking that was the issue. As it turns out, the glove compartment light was the source of the drain (I guess the glove box doesn't depress the switch sometimes). It's worth checking out, and saved me costly and unnecessary electrical diagnosis and repairs.

13th May 2004, 10:27

I have an 89 Eldorado, it is a great car and I love driving it. It really hasn't had any major problems, it does leak a small amount of oil however it is not anything to worry about. The problem I think your having is with the Twilight Setinal... if the light sensor is bad the lights will turn on at night and this will cause the battery to drain...

3rd Jun 2004, 01:00

I have a 1989 Cadillac Eldo. I love her and have had her for 7+ years. She is at 229,000 miles and is still a boss! I want to keep her, but have to get a family car as I have a small child now (minivan time) and I don't know how to make the repairs myself. She has been a great runner for me, but I too have had the battery drain down. This has been amended by just disconnecting the battery when I leave town.

14th Jul 2004, 16:19

Hi, I have a 1989 Cadillac Eldorado. The car runs and drives great. It has 80000 miles on it. The problem I am having is when you go out to start it in the morning it starts fine. When I shut it off you can't restart the car for about an hour to an hour and a half. I've been told it was the anti theft system. Is there anyway to solve this problem or unhook the anti-theft system? Christen.

9th Aug 2004, 09:44

This is for Christen with the car not starting again for an hour or so. It might be what they call a Cam sensor. I had this problem with a 98 Oldsmobile and it took them 3 hours to find out what the problem was.


24th Oct 2005, 00:17

I've had a few problems with my battery depleting itself as well. I found a few problem areas in the trunk latch, the antenna, and the light filtering device in the rearview mirror. Hope this helps.

4th Sep 2006, 15:42

89 Eldorado. OK, I have an 89, it's in mint condition.

1. If the car won't start after you turn it off, and you wait 20 minutes to restart. Yes, it could be the security system, the black plastic pin on your key gets worn out after a long time of use, so when you stick the key in the ignition, the security system does not detect the chip on the key. Go to your car dealer and have new keys made. They're about $100.00 for two.

Battery drain. You may have a faulty starter, or solenoid, which will drain battery after it sits awhile. Have an electrical load test on the starter and solenoid.

Hope this helps.


Glendora California.

22nd Jun 2007, 14:23

Hi, I have a 1989 Cadillac Eldorado. The car runs and drives great. The problem I am having is when you go out to start it it says starting disable wait 3 minutes. Is there anyway to solve this problem or unhook the anti-theft system? I've already had new keys made.