The trunk on my 91 cadillac deville won't close. I can see the latch going up and down to close the trunk lid. what should I do?

Hello James Squyres,

Of the 33 TSBs (tech service bulletins)...

I found nothin on your issue...

Going to the vehicle drawings... (I'm guessing you are considering keeping this beauty)...

Get the FACTORY+WORKSOP+MANUAL... I HIGHLY
recommend for drawing (exactly this issue) and easy secrets to get through those nasty UNIQUE Caddy tasks.. that NO body but your friendly CADDILAC Club might ALSO know...

Nevertheless...
your drawings are presently available on one of my favorite sites "BBB Industries: (see below, registration required).

Perusing the drawings...
The only source not shared with your manual ignition source appears to be through your "TRUNK RELEASE" function.. is sourced (without the ignition) through "THE TRUNK LID LATCH SWITCH"... (ground source).

I am thinking LATCHED (totally defective, replace) contacts there would cause your problem...

BUT... on further consideration...

The drawing show a total TRAVEL of the un-latched lock should completely open the ground circuit... reversing POLARITY of the motor and ready it for the LATCHING sequence...

To me...

It looks to be the trunk lock TRUNK-LID PULL DOWN MOTOR STRIKER SWITCHES... failing to release (change polarity) in the UP position...

Replace the "TRUNK-LID ADJAR" switch.
Everything SHOULD come up peaches...

As to why it is not an issue with manual control...
I'd need to be there with a Volt-Ohm Meter

(perhaps we could dialog)...

Happy hunting...

8/11/2016... post week-long silence

So... 9 DAYs later

little more dialog is not acceptable (?)
I'll go to my monolog:

If you don't know how to run a Volt-Ohm Meter
I'm wasting your time (GOOD DIGITAL $10).

Because of the POLARITY REVERSAL (to push the latch up (when radio-released))...
IS A GROND START SEQUENCE..!!

It is not reasonable to look beyond the mechanical contacts (which I ALREADY) noted... previously.

The full open motion
(at the end of the open cycle)...
Should push the contacts (to reverse polarity)... STOPPING THE UPWARD DIRECTION...
The battery contact (close sequence) is a BATTERY START SEQUENCE) is triggered by gentle push of the trunk lid into the LATCH.

It the travels down tightening the trunk-lid into place... and reversing the MOTOR POLARITY again at the FULL CLOSED POSITION

The ONLY thing that can keep the motor running is bad contact in the release switch... or (somebody) HAYWIRED it.

It would HAVE BEEN be nice to know if you UNDERSTAND the electro-mechanical nature of your lock assembly.

HAVE you done any rewiring (HAYWIRING) would be the PRIME CONCERN...

ELSE... It is the trunk latch contacts.

When last I looked ... those parts were still available...

and having spare parts for a collector quality car cannot be that DISTASTFUL...

I'd give it a TRY (I'm just saying)

BBB Industries Premium Alternators Starters Power Steering Products

http://www.rockauto.com/en/catalog/cadillac,1995,deville,4.6l+v8,1025323,electrical-switch+&+relay,trunk+lid+release+switch,4828

1995 CADILLAC DEVILLE 4 6L V8 Trunk Open Warning Switch RockAuto

More Information for STANDARD MOTOR PRODUCTS DS939

More Information for ACDELCO 16889150

check your deck lid release lever or trunk release button power supply inside your glove box . the trunk should open up with no problem. you may test it by hot wiring it if you have to,

Have a repair shop replace a failed
electric trunk lock assy

Inoperative trunk pull-down motors are very common on Cadillac. The sytem simply needs to be diagnosed. The most common causes are bad switches on the latch assembly (there are switches on both the body part of the latch and the trunk-lid part of the latch) or broken wires inside the wiring harness that connects the body with the trunk lid. Proper diagnosis required.

1. check the wiring
2. the latch may have shaken loose and you may have to tap the latch to re seat.
3. replace electronic motor below the latch.

it may be as simple as adjusting the catch.....cheers

There is a electric motor on the lower part of the trunk that usually goes bad. Not on the trunk lid but the trunk part. You can remove the assembly and take it apart so you can turn the latch all the way down , Once youy have done this you can put it back in place. Make sure you unplug the motor so it won't go up again, You should be able to use the release button inside.

latch mechanism is probably motorized. Gently pushing the trunk lid down slides the lid/latch bar into the mechanism. this pushes a tab inside the motorized latch and the drive motor pulls the lid down tight and secure. you may be able to test the latch mechanism by sliding a pen or screwdriver into the latch groove to simulate the lid coming down. if you see the motor drive engage, and pull down the tool, you at least know this is working.

If the latch on the deck lid does not catch your problem is the latch catch. If it closes and does not pull down you will need a pull down switch,

Replace thr pulldown switch .