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Technical => Electrical Tech => Topic started by: jpc647 on November 27, 2010, 06:32:38 PM

Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on November 27, 2010, 06:32:38 PM
My door locks on my 88 thunderbird keep trying to lock by themselves. The door locks themselves don't even move up and down, but I can hear the actuators trying to engage by themselves. Is there some kind of a computer which controls them? I tried disconnecting the battery to no avail.

If I try to lock the doors, it does the same thing, the door locks don't move but you can hear the actuators trying to move, happens on both doors.
Title: Door Locks locking by themselves-Problem Solved
Post by: Haystack on November 27, 2010, 06:50:51 PM
you need to tear into it to see what is wrong. All you have to do is pull off the door panel and then watch.
Title: Door Locks locking by themselves-Problem Solved
Post by: EricCoolCats on November 27, 2010, 11:15:13 PM
Door lock and unlock relays are under the passenger seat. Might want to check them.
Also it's possible that one of the switches on the doors is stuck and just keeps them in a cycle.

Disconnecting one of the above should yield some result and you can troubleshoot from there.

Do you have keyless entry?
Title: Door Locks locking by themselves-Problem Solved
Post by: 20thanniver-ls on November 28, 2010, 11:59:16 AM
This happened to me in my Mark. Turned out to be one of the pins pulled out of the connector behind the door panel and was grounding itself out on the door. Probably a longshot for you, but I think it would be worth checking.
Title: Door Locks locking by themselves-Problem Solved
Post by: jcassity on November 28, 2010, 01:52:09 PM
Its gotta be a relay,, could be one of the two door switches as well.

diagram available if you want.
Title: Door Locks locking by themselves-Problem Solved
Post by: softtouch on November 28, 2010, 06:16:01 PM
I seem to recall from previous threads that the 88's don't have the relays under the passenger seat. So if you don't find them there, they are under the center of the dash, I think.
Eric asked if you have keyless entry. This is important because with this feature, you don't have relays. The actuators are controlled by the keyless entry module.

The actuator motors have built-in circuit breakers. With continuous power to the actuator the breaker will heat up and open the circuit. Then it will cool off and put the power back on the actuator. I'm guessing you are hearing them cycling like that.

What happens when you try to unlock the doors?
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on November 28, 2010, 10:10:11 PM
I don't have keyless entry. The problem stopped, it is bizarre. I had the battery unplugged for a long time, reconnected it and they stopped.  I will take the door panels off and check for the pins grounding. The door buttons are not stuck, pushing them did not affect the problem. It's possible it is one of the relays, I will have to remove the passenger seat to check.
Title: Door Locks locking by themselves-Problem Solved
Post by: jcassity on November 29, 2010, 12:44:15 PM
Or, loosen the rear nuts, then remove the two front bolts so you can tilt the seat back.

My point was just like what soft touch was saying, your lock solenoids are constantly getting power so the internal circuit breaker is heating up and cooling off thus constantly adding and removing power.

Its gotta be a stuck relay or dirty contact on a switch somewhere.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on November 29, 2010, 01:08:03 PM
Jcassity, If I hold the lock or unlock button, it only activated the locks once, holding the button does not leave the circuit open, its seems to be a momentary thing. <-- Does that make sense? But your thinking it has to be a stuck or dirty contact on the door switch itself, correct?
Title: Door Locks locking by themselves-Problem Solved
Post by: jcassity on November 29, 2010, 01:37:40 PM
holding a door lock button closes or allows power flow.

something is stuck closed,, be it a relay or dirty / worn contacts somewhere.

it would not be a first to have a relay contact welded closed.  If the relay were arch welded in the closed position, then it probably is warm to the touch.

my first guess is like everyone said as well, get the door panel off and watch what happens.
who knows, you might find your wire harness is jacked up because your window up and down movement has rubbed a wire.

check out the evtm as well or the diy links in misc tech.  i think i have door locks posted there.

get a test light or rig one up and poke around.  you should not have any power going to the solenoids although we already know you must.  the only time they do stuff is when the lock/unlock button is pushed.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 05, 2010, 02:49:02 PM
Well apparently while I was at school again the problem happened. I do have a remote starter/door unlock. It may be the problem. I'm not sure. I removed the solenoids from underneath the seat, they look to be okay. The pins aren't discolored or anything.

I will remove the door panel next weekend, I don't have time today. I'lll get a test light and look to see what I can find. IF anyone else has anything, feel free to chime in.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 05, 2010, 03:16:52 PM
Update.. Unplugging one of the relays under the seat eliminates the problem. The relay itself looks okay, but when it's re plugged in the doors looks start  working. Seeing I locked the car when I left, and it was unlocked when I came home, I think it's safe to say the unlock switch is the one in question. Now does this mean the actuator is bad, or could this still be the switch?

On the two actuators, there is one closest to the drivers side, one closest to the passenger side. If the one closest to the driver is plugged in the doors start trying to unlock themselves, over and over again. The one of the passenger side can be plugged in and nothing happens. Nothing happens if the drivers side closest one is plugged in by itself. I'm making an assumption that they both have to be plugged in, in order to work, is this correct? If I try to lock the doors with both of them plugged in, nothing happens, is this because the unlock circuit is somehow open, and only one can be open at a time, or does it mean the problem is in the lock part, which is causing the unlock to malfuncion. I'm trying to understand how the system works, hoping that'll allow me to figure out the problem, i gues.

I know I have to take a door panel off and try to figure out whats happening. I'm assuming it's going to be on the drivers door, as that's the one that was taken off most recently. I thought the above paragraph might narrow it down a little to maybe and electrical guru here.
Title: Door Locks locking by themselves-Problem Solved
Post by: 20thanniver-ls on December 05, 2010, 03:33:08 PM
I *think* (and a good possibility I may be wrong - so somebody correct me ) but if the door locks are moving then I think the actuators are good.
Title: Door Locks locking by themselves-Problem Solved
Post by: softtouch on December 05, 2010, 06:05:32 PM
Your thread started with the locks locking problem. Now they are unlocking?

Yes both relays need to be plugged in for it to work.
Yes if the actuator motors in the door move the locks they are good.

The actuators are little electric motors. They run in one direction to lock and in the opposite direction to unlock.
When neither of the relays is picked (operated) they apply ground to both sides of the motors. When one of the relays is picked it applies voltage to one side of the motors while the relay that is not picked applies the ground to the other side of the motors. One of the relays is picked to lock and the other relay is picked to unlock.

The lock control switches apply ground to one or the other or neither of the relays.
A bad switch or one the wires from the switches being grounded can keep one of the relays picked.

Is the remote start/door unlock a standard feature or aftermarket?
Do you have any documentation for it?
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 05, 2010, 06:32:14 PM
Quote from: softtouch;344571
Your thread started with the locks locking problem. Now they are unlocking?

Yes both relays need to be plugged in for it to work.
Yes if the actuator motors in the door move the locks they are good.

The actuators are little electric motors. They run in one direction to lock and in the opposite direction to unlock.
When neither of the relays is picked (operated) they apply ground to both sides of the motors. When one of the relays is picked it applies voltage to one side of the motors while the relay that is not picked applies the ground to the other side of the motors. One of the relays is picked to lock and the other relay is picked to unlock.

Is the remote start/door unlock a standard feature or aftermarket?
Do you have any documentation for it?

Yes, I originally thought they were unlocked trying to lock but they are actually trying to unlock. Good to know about the both actuators needed to work. I unplugged one, and left the car.  I will look into the grounded wire, the locks keep trying to cycle, its not immediate, but it is like every 10 or 15 seconds.  The remote starter is an aftermarket one, I have an electronic owners manual for it I just downloaded form the company website. It may likely be either of the 3 possibilities, a bad relay, a bad/grounded out wire, or a bad switch. How can one test or see if it is the relay without changing it. I have plenty of switches I can swap in and out to test.
Title: Door Locks locking by themselves-Problem Solved
Post by: jcassity on December 05, 2010, 10:12:22 PM
dood,, ,,,,nevermind.

first off, unhook and disable this remote system and put things back to factory.
Im betting its your aftermarket remote. 

tell me the frequency its on isnt gonna be effected by other random radio waves jumpin around in the air.

how about this,,, drive out the country and see if the problem persists,, if not then you just found your problem.
Title: Door Locks locking by themselves-Problem Solved
Post by: softtouch on December 05, 2010, 10:28:10 PM
If swapping the relays causes the problem to change from locking to unlocking or vis versa, then one of the relays is bad.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 18, 2010, 01:43:30 PM
Alright, well I've been screwing with this all morning. I found the remote start/door lock unit that Rayco car electronics installed, I unplugged every wire running to it, the problem persisted.

I took the door panels off and unplugged both of the door lock/unlock buttons, the problem persists

I fished around inside the doors and unplugged both actuators, one at a time, the problem persists just with whatever door isn't unplugged. The drivers door makes a different noise than the passenger door, the drivers door unlocks itself, but it makes another electrical sound.

I keep unplugging one of the relays from underneath the passenger seat to stop the door from continuously trying to unlock. I'm out of ideas now, I now know the switches are not stuck, but what else can cause this? Is there a central brain for the locks? Where is it? Anyone know what could be causing this now?
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 18, 2010, 04:58:28 PM
Well I found the problem. While riveting the patch panels in the floor a couple of weeks ago one of the rivets, or the pilot hole drill must have tapped some of the wires on the drivers side next to the kick panel. Two pink wires and a white with black stripe wire to be precise. Well the must have been in contact with each other, and the plastic coated was chewed away and this cause the doors to keep unlocking by themselves. I cut the bad section out and soldered them back together, retaped the harness back together and when plugging the relays back in...... Silence! No locks unlocking.

So problem solved, I thank everyone for chiming in, another problem solved, another victory for Foxtbirdcougarforums!
Title: Door Locks locking by themselves-Problem Solved
Post by: jcassity on December 19, 2010, 10:11:14 PM
good thing,, had my eye on this one wondering if you really would find a live breathing grimlin.  thats about all that was remaining that could have caused this.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 20, 2010, 06:18:56 AM
Quote from: jcassity;346288
good thing,, had my eye on this one wondering if you really would find a live breathing grimlin.  thats about all that was remaining that could have caused this.

Thats for sure. And just my luck too, it's always the last possible one that ends up being the right one.
Title: Door Locks locking by themselves-Problem Solved
Post by: 20thanniver-ls on December 21, 2010, 07:25:20 PM
Quote from: jpc647;346300
Thats for sure. And just my luck too, it's always the last possible one that ends up being the right one.

Hey I suggested checking the wiring on the first page.... wasn't exactly last possible thing....LOL Glad you got it figured out. It drove me nuts when I had this problem with my Mark. It even killed my battery overnight.
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 21, 2010, 07:52:12 PM
Quote from: 20thanniver-ls;346448
Hey I suggested checking the wiring on the first page.... wasn't exactly last possible thing....LOL Glad you got it figured out. It drove me nuts when I had this problem with my Mark. It even killed my battery overnight.

I read about the grounding suggestion behind the door panel, which I checked when I took the door panels off. This was in the wires at the kick panel. But just the same. My battery was dying overnight too.
Title: Door Locks locking by themselves-Problem Solved
Post by: 20thanniver-ls on December 21, 2010, 10:19:25 PM
While it was happening on mine I was at the shop getting new tires freaked the dude out a little, the shop dude thought I was insane for putting new tires on a "busted 'ol car"
Title: Door Locks locking by themselves-Problem Solved
Post by: jpc647 on December 22, 2010, 11:49:04 AM
Quote from: 20thanniver-ls;346474
While it was happening on mine I was at the shop getting new tires freaked the dude out a little, the shop dude thought I was insane for putting new tires on a "busted 'ol car"

Yeah, I get that too. But I keep thinking that even though this busted ol' car isn't the prettiest, it isn't the fastest, and it got more problems than I can shake a stick at, I'll just keep plugging away at them, with the help of you guys, and I keep thinking about that $400 a month car payment I don't have. I figure if I buy another car, it should be new. With a warranty and all that, and until I can do it in cold hard cash, I won't.