1998 Cadillac Deville with Northstar


I've searched the forums and maybe I missed it but haven't found the answer. Maybe there isn't one.

I have a beautiful 98 Cadillac Deville in mint condition which we love. It had been performing perfectly for the past year of ownership. And then an electrical problem showed up out of nowhere.

Now and then something will quickly drain the battery. This may happen overnight or after it has been driven all day long.

Here is what has been done so far.

Alternator and starter checked out at an alternator shop.

Installed new battery just in case

Unplugged the CD changer in trunk.

Local Cadillac dealer had car for ten days when they checked out all possiblities and thought they had found the problem to be the old phone which wasn't even present anymore. They disconnected that component and called it a successful repair. When I went to pick up the car it wouldn't start, had to be jumped. They insisted the battery was bad.

Left dealer and had battery checked at TWO different places. Battery tested good.

Took to another shop where it stayed for over a week with a meter on the negative cable. Showed typical draw for the first minute of so and then would drop to normal. Mechanic drove car off and on while it was there and said he never had a problem.

Got the car home and began using it. A day or two later same problem persists.

There are no aftermarket parts on the car. It's all factory standard.

I'm to the point of getting rid of the car but we really love it. Any help would be appreciated.

 

check power antenna for drain, there are a couple of good electric ghost guys here, I'm sure they will see you post soon.

 

you may be looking in all the wrong places.

the main suspects:
- power antenna,
- power locks,
- power trunk pull down,
- power mirrors,
- theft deterrent system,
- relays
in other words, powered items that you dont usually touch
but are activated via another mechanism like relays and solenoids.

i be pitting an amp meter on the electrical and
start pulling fuses one-by-one and see which one
makes the change in current draw.
then you got something to start with.

if you dont get any current drop after pullign all the fuses,
i be scratching my head and going for grounds, specifically
BUSS terminals, harness connectors.

do remember to read:
https://www.cadillacforum.com/m_6068/tm.htm

as a lst ditch effort, trow your hands up and install a battery tender ..

 

Thanks for the suggestions. I'll start the quest.

 

If you haven't found your gremlins yet... you can start do***enting the "end of your Cadillac's day", that is the steps you've made just before tucking in your Caddy for the night. Like... Put in Park, applied Parking Brake, turned off ignition, opened trunk by button on console, closed sunroof, locked door by RKE fob, closed trunk lid, etc. Then, when the life of your battery gets sucked dry, find what you DID prior to the drainage and NOT in previous nights when nothing happened. This is not for the imaptient type, though.

 

Hello,

I'm back for more suggestions.

I fully charged the battery.

I removed the following fuses in the trunk.

1. Antenna
2. HTD Backlt (whatever that is)
3. Trunk Pull Down
4. HTD Mirror
5. Radio Phone

After the car sat for a day the battery went down again.

Am I correct that if the fuses are removed it would prevent those individual systems from operating and draining the battery?

I didn't find the fuse for the remote door unlock or didn't know what label it would have. I haven't tried the seat heaters but they are not heating the seats.

I also thought it might be just as well to leave out the Radio Phone fuse as I believe that item is outdated and not used anymore. Is this correct or does it control something else as well?

I've had the alternator checked. Has anyone ever had a starter drain a battery just sitting unused?

 

you really need to find ALL the fuses and hook up an amp/volt meter to do this..
Radio Shack has some nice digitals for $19.

if you dont, your mechanic will do it @ $125 / hr.
5 hrs of labor is not unheard of....

or give it up and get a battery tender .. many owners do this option.

the starter? never heard of that.

 

OK, I'm not oppossed to giving up and installing something to keep the battery from draining. But unless I'm wrong a battery tender requires electricity just as a battery charger does. And we are not able to plug the car in every time we make a trip in it. We bought the rechargable jump battery to keep in the trunk. But that is a pain too.

This is not a problem which can be solved by charging the battery every night and running all day. Even though the alternator is recharging the battery now and then when you go somewhere and park the car something will totally drain the battery within a few minutes. And even worse it doesn't happen all the time.

I had already taken it to the Cadillac dealer who put a meter in line with the negative cable on the battery and they claimed they solved it by disconnecting the old phone system which was built into the car. I took it to another mechanic and he kept a meter on the battery for over a week and the problem never even showed up. He even drove it around some on some errands trying to make it appear. A week later I bring it home and there it is again.


It's one of those kinds of problems which make me want to pull out my hair.


I am wondering if when you disconnect the battery cable to put a meter in line if it resets something and the problem goes away for a while. It's really weird.

I think I've found all the fuses under the hood and in the trunk. I don't have a book on the car. I just thought someone else may have had the same problem and offer a suggestion. I'll just remove a different set of fuses and go through another day to see if it turns up.

 

just curious if you ever found out what was causing this my car is doing the exact same thing

 

Go park the car near somewhere you can sit awhile, preferably at night. Pull up a chair on the porch. Ensure all the doors are closed on the vehicle. Watch the interior lights. If they come on for 20 secs then turn off and repeat that every minute then your interior lighting module has crapped out. This module may also be known as the RAPIE module. You can't buy new ones This was the source of my Seville's battery drain though mine was a 92 model and on your 98 they may have eliminated it. You'll know it's the problem if the interior lights blink on and off though.