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Discussion Starter #1
Hi experts,
I bought a 93 DeVille just 2 months ago. Worked fine until 2 weeks ago.
But now the battery gets drained within a couple of days; I just checked the drain current and found it to be 400mA. Whenever I connected/disconnected the AmMeter to the battery, I heard a click, which came from this device:

I suppose it is the AC. As you can see, I've disconnected it; the remaining current leakage is just 30mA, which I consider to be ok.
Now, the questions: Am I right, is it the AC? If yes, am I safe with leaving it disconnected? Can I just leave it as is and drive and enjoy my car without anything major failing? Thanks for any replys!
PS: I apologize for my english, I am no native speaker.
 

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White Diamond '03 DHS (with DTS floor shift)
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:welcome: No, that is not the A/C compressor. It is the ELC (Electronic Level Control) compressor. It is draining your battery because there is a leak in one of the lines running from it to the rear shocks or in one of the rear air shocks. When it bleeds down, the compressor turns on and pumps it back up. This cycle continues till the battery is dead. The worse the leak, the more frequently it will run.
 

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Hmm that I know of hte compressor is only supposed to run for a few minutes after the car is shut off it is not supposed to keep going on and off to keep the car level when it is not in use especially because over long storage times this would drain the battery considerably.

First things first are you waiting 20 minutes after connecting the ammeter on so that you can let the electronic modules shut down?

you have to wait for at least 20 minutes so the car goes in storage mode so it "sleeps" then check the ammeter I am sure that an acceptable level is supposed to be .01 on a multimeter

The method I used to diagnose my problem was first start pulling the big (30-60 amp) fuses and then once the amps fall to the acceptable level I checked what fuses ran off that 1 big fuse and I found out it was that my blower motor was faulty causing the computer to turn on and stay on all the time causing my battery to go dead.

I replaced my blower motor and the battery kept draining so it turned out that the optima battery had gone bad too although it was 3 months old but because of the excessive draining and sometimes completed dead battery it went bad. I exchanged it and for a month now had no problems at all.
 

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Discussion Starter #4
@Ranger: Ok, so its the ELC compressor. I probably don't want the car to run without it? But when I connect the ammeter, it just clicked, it did not run or anything, just clicked once and the 400mA leakage appeared.

@ocjmakaveli: Do I have to wait for 20 minutes although the car was standing for hours and I just disconnected the battery and immediately checked the current? Does that mean that whenever I reconnect the battery, all the electronical stuff will wake up and turn itself off only after 20 minutes? Why's that? And, does that mean you think it is ok that the compressor turns on when connecting the meter?

Thanks again, folks! Do I have to replace one of the shocks? The front shocks don't operate on air?
 

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'80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
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400 mills sounds like a solenoid. Maybe the vent solenoid is built into that compressor and is hanging on for some reason. The compressor motor itself would draw several Amps easily and burn up very quickly if not spinning.
 

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Discussion Starter #6
Ok guys,

Apparently that compressor is not the culprit. I reconnected it, connected the ammeter to the battery and after 25 minutes the current had dropped to ~20mA.

I wonder what the heck is draining the battery! Two weeks ago the car won't start because the battery was totally dead. I changed the battery. The new battery was totally dead again yesterday, after the car stood for about 5 days. Now the leakage is only 20mA, that certainly does not empty the battery within 5 days.

Are there any creeping current defects this car is famous for? Any that occur, then vanish again and occur again? What strategy do you recommend for finding the culprit?
 

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White Diamond '03 DHS (with DTS floor shift)
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Connect your ammeter again and start pulling fuses til you find the one that is causing the draw. Then at least you'll know what circuit to look at.
 

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guill yes you have to wait 20 minutes every time the computer wakes up

youll have to pull fuses until it gets low at least 10 or less and sometimes when u reconnect a fuse the amps might jump up again so that means the computer woke up then youll have to wait another 20 minutes until it settles down to about 20 amps.

Some of the things I've read on here that go bad are Stock radios, remote function actuators(remote keyless module) , trunk lights can remain on after you close the trunk, then there can also be a short if a wire is touching the body itself it could be grounding and draining the battery

For now though start pulling the small fuses and take your time watching the ammeter closely pull them out one by one and check until you see the amps go down once they go down you can tell us which fuse it is or check in the FSM for what devices run off of that fuse.

Also disconnect the blower motor that might be the culprit I had the same problem a month ago.
 

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Discussion Starter #10
Ok, apparently I haven't been clear: There is no drain anymore, at least no greater one than 20mA after the battery is connected for more than 20 minutes.

I wanted to pull fuses next, but as there is no drain at the moment, there is no point in doing it.

@ocjmakaveli: By blower, you mean the one that blows the warm or cold air into the passenger cabin?

I should give some more info on the car: Whenever I turn the lights on, the clock, the climate control display and the fuel usage display start to blink and stay blinking until the lights get switched off again; sometimes the blinking stops for a while, with the displays fully on or off. The Radio does not work at all, neither does it turn on nor does the antenna come out (The fuses are like new). The right "turn illuminator" does not work either, nor does the hood lamp (bulb is good). These are all minor things but I thought maybe one of the circuits involved is the culprit.

The problem is that the problem seems to vanish and reappear at unknown intervals ... those kind of problems are difficult to solve, since you never know if it is there or not at the time you are trying to find it...
 

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From your last post, it sounds like you may have a bad body control module. That could be both the blinking/no radio problem and the battery drain problem. I just saw the exact same symptoms on a 2001 Monte Carlo and replacing the BCM was the solution. Look for codes. The bad BCM should set some kind of code.
 

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Guillaume said:
I just checked the BCM Codes (as described on http://www.cadillacforums.com/forums/showthread.php?t=21558): It shows me 888,..F,F10,.F.F,F10,.7.0 (in this order). I suppose the only error I have is F10, which is: Outside Air Temperature Sensor Circuit. That is not surprising, as I cannot get the Outs. Temp. displayed.

Oh man, I don't know what to do...
I don't know much about OBD-I systems or how to retrieve the codes, but I do know that on the OBD-II Monte Carlo I worked on showed a U1064 code that led us to the bad BCM module. I don't know if there is an equivalent code for OBD-I or how it would be read. Maybe someone else will chime in here with an answer on that question. I'm still leaning on a bad BCM as the source of your problems just because the symptoms are exactly, to the letter, the same as that Monte Carlo. Flashing lights, no working radio, dead battery, all the exact same stuff. If the BCM is the problem, you'll need a new one. For a '93 DeVille, you need AC-Delco BCM part number 88999226. Rock Auto wants $97 for the BCM and a $67.50 refundable core charge (send in your old one for credit). Once you have it replaced, it may need to be programmed by a dealership, but I don't know that part for sure.

Here's the part at Rock Auto:

http://www.rockauto.com/catalog/catalog.php?carcode=1025750&parttype=2888
 

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88 Sedan Deville, 89 Eldorado, 11 SRX, 18 CT6
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i seriously doubt it's ECM or BCM related. check for a dead or shot twilight sentinel module. the most simple way to check, reach up there's a white box held to the plastic vent under dash. there is a wire harness going into this. disconnect this, then turn lights on. do your dash still flicker? turn brightness knob on headlamp. if that's faulty, it can cause that. radio is dead? take it out look at the wires. make sure there all disconnected. see what happens. you have more then one electrical problem, could be a wire touching metal (as stated previously by someone else) after time stuff comes off! it happens. take your time, you'll find id. and when you do, your probably going to ask yourself "why the heck didnt i think of that before!"
 

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what is an acceptable ma range? is teh 20 ma he is posting ok?

If it is then I would also suspect a unit that controls all those functions you are saying is bad.

In this case that you have multiple things going bad I would suggest going to a dealership.
 
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