'92 Ultra strange power cycling and drain

My batteries are being eaten alive! Well, AZ's batteries are....I've traced the fantom power drain to fuse #3 on the relay panel behind the passenger dash. It cycles every 20 seconds to 4.5 amps then back to .04....every 20 seconds. I don't have a PA manual with schematic. Was wandering if those that do could help me out. I pulled all the relays and the RAC and nothing changes. Maxifuse 7 kills it and #3 on relay panel. Was thinking maybe the instrument panel dimmer or sentinal. Some kind of timer that cycles......Help! and Thanks.

This sounds like the Electronic Level Control (ELC) compressor is the culprit. Can you here, or feel the compressor under the hood running every 20-sec. If so, pull fuse #12, labeled (ELC) which is located in the fuse panel under the drivers side dash. This will deactivate the system until the air leaks (probably struts) are repaired/replaced.

My thoughts exactly. Unfortunately I don't think that's it. Well unless the timer circuit or level control switch will cause a power drain with the pump disconnected. I have recently replaced the struts as my pump was kicking on even with key off. That didn't even kill the battery overnight. That problem (leak) still exists and I haven't found the leak yet. Might just get the Monroe kit to bypass the pump. Pump connect is pulled. I pulled #11,12,21,24 and no change until I pull #3 in the relay center. So right now I have the #3 fuse pulled from the under dash, passenger side, relay center. The ID on the label lists a few things...Illuminate entry...interior lights...door locks...remote door lock and power antenna. With that fuse pulled my IP lights fine, sentinel works, door lock works but not the driver's...don't have a radio to call for antenna. The really curious part is the cycling...every 18-20 seconds. If you have a schematic, I'm sure there's a timing device I need to locate...

Sorry, I do not have a year/model specific schematic for the ELC system. IIRC, the level control switch has a separate power supply and is not connected to the compressor harness. The compressor relay is activated by the level switch which has a timer circuit built in. Try disconnecting the level switch harness and put fuse #3 back in and see what happens.

Sounds like a good idea. Where is the level switch located....or the other end of wire for the switch.

The level switch is located under the Right Rear (RR) of the car. You will see a switch arm and actuator rod connected to the RR lower control arm. The terminal is located just above the switch. It can be difficult to reach from under the car, so it might be better to remove the RR tire/wheel for easier access.

I'll give it a shot this weekend and report back. Thanks.

No go on the switch disconnect. Even heard my pump kick on the night before....must still be a leak. I bought the AK29 kit. Thinking of bypassing the whole auto adjust system on this old beast.

Thought maybe it was the dash dimmer or sentinel but I disconnected these and no change. Noticed the cycling changed a bit.....the following in seconds...

on off
36 9
27 9
18 10
18 10
18 10

Almost like something is heating up? Connection breaking down?

Guess I really need the schematic to track this down.

Did some more testing today. Seems like the only thing that's not working when fuse #3 on the relay panel isn't working is the door locks. The driver door lock hasn't been participating in the lock party when the interior door switch is activated. I disconnected that switch on the driver's door with no change. Didn't tear into the door to get to the locking mechanism itself.

So....wondering if it's that door lock or maybe something with the security system. Is the longer "on" at the beginning just happening before a sleep mode? Maybe monitoring malfunction?

Anyway, with the #3 fuse pulled, everything works, except door locks, and battery isn't drained. Even with the suspension compressor kicking on once in a while....

Does the power trunk release, radio antenna, fuel door & rear defogger work with #3 fuse pulled? Most of these power options share & use a circuit breaker to protect the windows, locks and other power accessories. When the current load is too high, the circuit breaker opens until it cools down enough to close & restore power. You may have a ground short in one of the door solenoids. These circuit breakers are located in the drivers side fuse panel. You should be able to feel the breaker overheat before it trips. Put fuse # 3 back in (once more) and feel the circuit breaker for excessive heat & tripping. Good Luck!

Found it!

Put the #3 fuse back in...felt the breakers you described...not much heat...what was that?....click...wait some time....ping!....Ah, a relay...where is that dang thing...

Now a lesson in acoustics, yes acoustics.....heard it in the dash...right side...no...center?!!...wait....it's in the back by the window defrost switch....HA! replaced one of these suckers on a '97 Lesabre...tear into the rear trim....no switch?!!...but I hear it cycling...click....ping....been here done this!!!...OK seems to be more in the center....no, in the trunk...stick head in trunk...right side....no, center...can't locate it...peal back more covers...can't find the dang relay....OK, after trying every area in the back seat and trunk, I was sure it was the trunk.....right side....ouch that antenna motor is WARM....FOUND IT!!....coulda sworn I heard it in six different places!...acoustics.....

Thanks for staying with me on this one HotZ. Don't know what the final solution is yet but I'll get to that another day. Guess the relay first....or just get a replacement antenna.

Can't believe it was the antenna as I don't have a radio in. Just a faulty relay? What caused it to cycle? Antenna is probably jammed.

Thanks again. Hope the visual was entertaining!!


Now to put my car back together.

Z, would the radio not being installed cause the antena to be activated?

Z, would the radio not being installed cause the antena to be activated?No, because the antenna relay is activated by the radio ON power output.

Z, I'm confused,if the radio is not installed what is powering the antenna?,could the relay be bad? thank's Frank

Yes, if the antenna failed while trying to extend/retract the relay may be stuck closed. I would pull the relay and exchange it with another one (not the fuel pump) from the same area to see what happens. It might be better to disconnect the wiring harness to the antenna until the problem is resolved, or a replacement installed.