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In 30 years I've never seen this one, I hope someone on this list has.

I just finished a 4 month long brake refresh on my '85 street car. Naturally, when I reconnected the battery it was mostly dead so I put it on a charger, but couldn't get interior light to confirm I was really charging. On a whim I switched it on to the "start" position and the lights came on but the rear hatch release started running continuously. I tried closing the hatch, no joy, the motor kept running.

I quickly switched back to a 12 amp (fast) charge setting and was able to close the hatch.

Then I used the key to open the drivers side door and the rear hatch opened. I shut the hatch, relocked the doors and tried again. As soon as I opened the driver's side door the hatch opened. Now I have the car locked, rear hatch closed, charger on 2 amp (slow) charge and can only hope things will be better in the morning.

I went through all the permutations I could think of, closing and re-opening doors, closing and re-opening the hatch, nothing seems to work.

I expect this is a security "feature" of the car I've never encountered. Any ideas about the best way to reset things?

Thanks,

Kevin in Atlanta

All I can think is one of your hatch switches is stuck open.

Alan

Yes the hatch switches are only enabled when the doors are open - so if a switch is stuck closed - it will activate when the door (either one) is opened.

Alan

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OK. I'll look at the parts manual an find the hatch switch. Clues welcome.

Thanks,

928Myles

Hatch switch is on floor between front seats and doors (Both sides). Beside handbrake on drivers side. Equivalent place on passenger side.

Myles

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Thanks Alan, Myles & Tiberon. I'll open up the hatch switch and check it in the morning. I suspected the alarm system because when I opened the passenger door the alarm went off while the hatch motor was trying to open. Who would have guessed the car would turn on the alarm and open the luggage hatch at the same time?

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What about the hood switch? Could that also engage the hatch? Since I have the car on a charger the hood is open.

Thanks,

mdkelly1

Check the "surround" where each hatch switch is mounted to be sure it is not slightly deformed or depressed downward. It will be hard to discern visually, but if the hatch lock is cycling continuously with the door open, reach down and gently insert your fingers under the surround and pull up slowly to see if the continuous cycling stops.

Don't know if that is the cause of the problem in your case, but it happened to me and it was a simple fix to pull/form the thin metal surround back to its original position.

When sitting on the door jam fixing other things, it is easy to inadvertently depress the metal surround without knowing it.

Wisconsin Joe

It shouldn't. The hatch release is tied into the interior light circuit. In theory, the hatch motor won't cycle unless the interior lights are on. Pulling the fuse for them will disable the hatch release, IIRC.

Randy V

Why would the hood be open to charge the battery? The battery is located in the back.

You shouldn't charge the battery using the under hood hot point.

Alan

Sounds like you have an alarm problem....

My car actually came with one that was similar... unlockling the hatch caused the alarm to go off, and conversly I discovered later that locking from the hatch (yes the key turns that way and you can lock the doors from there) actually unlocked the doors...

I discovered that the 3 pin mating connectior in the hatch for the lock had been forced together backwards - you weren't supposed to be able to do it - but someone managed anyway.

Maybe your passenger door lock doesn't turn off the alarm or maybe its connected backwards too...

Test how it works on that assumption... the hood open might trigger an alarm but it doesnlt change the alarm state (armed or disarmed).

Alan

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This wasn't the exact problem, but was so close I was able to figure out what was wrong.

When you take the tool kit out there's a bundle of wires running into the hatch release motor. Either while I was reconnecting the battery or just re-installing the tool kit, the wires got pushed together and connected a hot wire to the motor, looks like the wires aren't insulated all the way down to the posts they're soldered to on the motor so an uninsulated wire was touching the power post. As soon as I opened the door, the interior lights went on and powered up the hatch release.

All I had to do (temporarily) was straighten the wire run and carefully re-install the tool kit. I think I'll open it up and insulate those wires asap.

I'm really happy it didn't have to do with the alarm system, I've never completely understood how it works and frankly live in fear of it. Right after I bought the car in '86 I took it to a hotel and one of the bellmen set it off opening the hatch. It sat there honking for 30 minutes while I frantically called the dealer for instructions. Never want that to happen again. Thanks for the detailed explanation Alan, it will probably save someone in the future.

Thanks again to everyone who made instructive guesses, you saved my wife's vacation, I needed to get the 928 of the rack so I could do an oil/filter change on her truck before she leaves tomorrow. If I hadn't gotten the car off I could have been in a lot of trouble

Regards,

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Oh, and to Randy-- I usually connect the charger to the jumper post in the engine bay and ground it to the engine block. It's a lot easier than taking the spare out and opening the battery box. Since I keep the car on a maintenance charger almost all the time it's a much better solution for me.

Alan

With a trickle charger/maintainer that is quite OK to do.

Better to connect closer and vent the battery box (open lid) with a medium current charger

Also it's good to look at the battery very one in a while - esp the terminals, but also the case shape & venting...

Alan

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I've been using Deltran "Tender Chargers" with good results. I have one on the 928, another on the Audi and one on my backup generator. The generator tender failed after about 4 years and it was embarrassing because I have a solar array with battery backup and of course propane generator backup for times the sun's down. The whole system failed because the tender charger on the generator went runners up and I didn't notice, we had a 2 week grid failure and I was on vacation, the system is supposed to be automated but when the batteries dropped below threshold the controllers couldn't start the generator because the starter battery was dead.

I blew through $5000 in deep cycle batteries and two freezers full of food in about 12 hours because a $25 tender charger failed.

Otherwise, my experience has been good.