For some reason my "door ajar" light on the dash stays on all the time. I have checked the rear door switches and using an ohm meter, they appear to be working correctly. I'm at a loss where to look next to solve this issue. Any thoughts or anyone who has had a similar problem?
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Re: 69 "door ajar" light
There is an electrical latching mechanism on the back of the instrument bezel that can fail. Be absolutely sure none of the pin switches are picking up a ground first -- as that is the easiest to check. Removing that instrument bezel is almost, but not quite as bad as removing the power brake booster.Terry -
Re: 69 "door ajar" light
Terry, do you know the purpose of this "electrical latching mechanisim"?Comment
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Re: 69 "door ajar" light
It keeps the light on until the button below the light is pressed. Pressing the button "unlatches" the mechanism. Ordinarily I would call it a "relay," and it is -- but if I call it that it will conjure up images of something different than what it looks like. If you can wait until the weekend I think I have a loose instrument cluster that I can photograph.TerryComment
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Re: 69 "door ajar" light
Terry, I'm confused a little. Isn't that for the seat belt light? How does that affect the door ajar light? JimComment
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Re: 69 "door ajar" light
DUHH! You have every right to be confused because I am too. You are right, and I am wrong. I don't know what i was thinking of.TerryComment
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Re: 69 "door ajar" light
Jim:
Did you check to be sure the switches are all being depressed when the doors are closed? Try depressing both switches by hand (you on one side someone on the other) and see what happens. If this is not the problem, remove the switches from the jam and inspect them. The plastic end could be broken allowing contact of the wires, grounding, etc. Just some thoughts.
JeffComment
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Re: 69 "door ajar" light
My 1971 had that problem. There is a rubber bumper about three quarters of an inch square that is glued on the inside of the door opposite the switch. When you close the door the bumper presses on the switch shutting off the light.
To test leave the drivers door open and press the switch in. If the light goes out , you have an answer. I know Paragon carries these.
hope that helps...JimComment
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Re: 69 "door ajar" light
If memory serves, the rubber bumper(s) were a running change 'improvement' that surfaced circa late '70/early '71. This thread deals with a '69 and my memory says they weren't used on cars that early. But, the descriptive text of the Judging Guide should confirm/verify.Comment
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Re: 69 "door ajar" light
Yep, your recollection is reading on the seat belt vs. door ajar circuit, Terry. The seat belt warning lamp is powered through a conventional relay wired in a 'self-latching' configuration.
On ignition switch activation, the relay is de-energized and the warning lamp comes ON. When the PUSH button is depressed, the relay fires and the output is tied to the relay's trigger line causing it to remain 'latched' for as long as ignition switch power persists. When the relay is latched, power to the warning lamp is open circuited causing the lamp to extinguish.
The circuit resets itself when the ignition switch is turned OFF and the relay collapses from power starvation. The cycle repeats the next time the driver switches the ignition ON...Comment
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Re: 69 "door ajar" light
There are two common causes of this (door ajar warning lamp stays on all the time):
(1) There's a short somewhere in the door ajar switch wiring system causing one or more lead wires to touch ground independent of the switches they connect to. Pull the switches and physically inspect the integrity of insulation on the attaching wires.
(2) The switches have been removed for whatever reason(s), often times during restoration body work and/or repainting and re-installed without being 'reset'. More...
Both the door ajar and main door jam switches are moderately 'smart' as they were designed/constructed to be 'self learning'. The plunger shaft makes an interference fit inside the switch's mounting nut. It can move fore/aft on the mounting nut to absorb or 'learn' the specific dimensions of a particular door gap.
When the switches were factory fresh, the plunger shafts were FULLY extended from the mounting nut (nut all the way BACK toward the switch contact area). They were wired to the harness and screwed into the door jam's mating receiver.
Then, the door was SLAMMED shut. That caused the door to press against the plunger shaft and push it back into the door jam relative to the mounting nut via the interference fit. Each switch 'learned' the specific dimensions of its specific installation point.
If a given switch is removed and re-installed in a different location OR the door was removed from the car and re-installed with a slightly different shim setup, the door gap probably changed... It may have changed enough that switch fails to go open circuit when that door closes UNLESS the installer took pains to re-set the switch to its factory fresh, plunger fully extended position so it could 're-learn' its new door gap dimension.
There are two switches (LH and RH door). They're wired in parallel. They give contact closure to ground when the door is open and that illuminates the door ajar warning lamp. It takes BOTH switches to properly depress and open circuit the warning lamp for it to go OFF.
But, of course, you all knew these common facts...Comment
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Re: 69 "door ajar" light
Yea, I know how it works Jack. Not unlike the latching of the alarm circuit.
My problem was I saw "door ajar" and thought "seat belt." I don't know why. Just a senior moment I guess.
TerryComment
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Re: 69 "door ajar" light
Hey, I've suffered from those hiccups too! Seems there was always a helpful fellow member to tap me on the shoulder and point me in the right direction...
My descriptive text was added for those who might not understand the concept of a 'self latching' relay (one whose output is simply tied back to the trigger).Comment
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Re: 69 "door ajar" light
Thanks everyone for your help, I got it figured out and it's working properly. I won't go into specifics but I was obviously making the job more complicated then it was. I earned the DS award for the day.Comment
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TerryComment
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