Current Drain 1976 Eldorado

[Jeff Pendleton 22056]

A small current drain is killing my battery in my 1976 Eldorado Convertible.  What I'm seeing a is very dim glow from the underdash courtesy lights and the small lights in the door that illuminate the keyhole via fiberoptic cable.  I know there is a feature that lights the keyhole for a period of time when you press the button on the handle.  Where is the timer for that or solenoid or whatever?  Maybe that part is bad or the ground is bad or something.  The lights seem to dim slowly from full brightness when the door is open to a dim glow, but never go completely out.  Hopefully someone can help me out here.

Thanks, Jeff

[Dave Shepherd]

There is a timer/relay/module to operate the coutesy lamps, memory is fuzzy here, I believe it is under the l/s of the dash, a shop manual is the way to go here.  Someone may kick in here with more precise info.

[Wayne Womble 12210]

I don't know where it is on the Cadillac,. but it is the most common cause of battery drain on Corvettes of the same era.

[Jeff Pendleton 22056]

Okay, I kept working on this myself and here is what I found...I noticed when I stepped on the brake that the dim courtesy lights would go out.  This also happened if I pushed on the steering wheel or even the floor!!  I frinally figured out that it was me pushing back on the seat (not pressing the brake, etc.) that caused the lights to go out like they should.  Because the car is being restored currently, and I'm just moving it around in the driveway, the driver's seat was installed with only a couple of bolts.  My theory is that this created a weak ground for the power seat and the seatback release solenoid.  A couple more bolts and a tighten-down all aroung and presto.

My final question for the wizzards out there is why did a loose seat cause the coutesy light to stay on, yet dimly.  And is something similar happening with the Corvettes as Wayne notes?  Maybe a replacement carpet set interrupting the ground?

Anyway, I'm happy now to have my courtesy lights going out like they should.

[Dave Shepherd]

The ground wound up following the path of least resistance so the nearest one was the light circuit.  Your theory is most likely correct.

[Jeff Pendleton #22056]

Well MAYBE my current drain is fixed... but now that my courtesy lights go out, I have another problem:  when I press on the button on either door handle to open the door the courtesy light timer (hidden behind the driver's kick panel) makes a buzzing sound.  I thought at first it was the security system, but its definitely the timer making the sound.  Anybody have a good timer for sale?

Also having a problem with the headlight dimmers.  Even with the guidematic switch off I can not get the lights to go to bright...unless I click the headlights off and back on then they go to high-beam instantly.  This works every time.  Can not get them to hi-beam at all with guidematic on.  Not done tracing this out yet but does not match any of the failure tests in the manual.  Yes I have both the Chassis and Body service manuals.  Still tough to figure out, and I'm a pretty seasoned troubleshooter.

Okay, time for my confession: When I replaced the battery recently I reversed the polarity briefly due to the cables having the opposite color coding (red was negative and black was positive!)  Who knew?,  I'm sure I blew a few diodes, and I'm just having to trace out all the problems and fix them.  Any help is aprpeciated.  What else have I screwed-up?  I think the alternator is bad...

[Dave Shepherd]

Any units powered all the time are in jeopardy yes the alt may be one, but look at a wiring diagram and see what is powered up key off, not much on the older cars.

[Jeff Pendleton #22056]

I THINK this is all fixed now.  Turned out I had three problems, which always makes it more difficult to trace. 

Problem 1: The door switch for the passenger seatback release was out od adjustment and was holding the solenoid in the "on" position all the time.  Drain # 1 Fixed.
Problem 2: I was restoring the car so I had the door panels off while the car was in the body shop. In the process the bulb for the passenger ashtray was crushed via hanging wires when the door was closed.  This was causing the body fuse to blow.  Replaced bulb.  With he body fuse out and the crossed wires at the bulb somehow it created a grounging problem for the courtesy light timer with resulted in the underdash courtesies and illuminated entry bulbs staying on with a dim glow all the time. 
Problem 3: did not show up until I put the rear quarter trim back in, but the driver's side lighter hot wire was grounded against the case creating another reason for the fuse to blow.  Had problen 2 and 3 at the same time so that did cause a little confusion.  Did get some help from another discussion of a similar problem on a seville where someone said they had a foil gum wrapper in the lighter socket.  That caused me to look real close at the lighters.

Apparently I got off the hook on the reversed polarity at the battery.  At least for this system.  I'll open another discussion for my wierd high-beeam problem.  Getting there though.
Jeff