redrdstr72

FWIW, all 1972's had a factory installed alarm system. Was an option in prior years, standard for '72 and beyond .

65GGvert

Alarm off/on switch:

OZvette72

... was suggesting a place for Ruken to look if he wasn't sure. It could have been removed and sold or tossed out.

Mooser

I'll have to look at mine to see if it's connected to the door-ajar or not.
No...wait. The hood isn't on the car and I've been testing the dash lights and I know it doesn't actually light up.
Hmmm, OK, time to check the wiring diagram
M

OZvette72

My '72 hood switch makes the alarm go nuts but I've never looked to see if the door ajar lights are on .... what? .... that's just crazy. Someone breaks into your engine bay and the interior lights come on so you can see what you're doing trying to steal the radio. That I am going to check out in the morning for sure.

Mooser

Well it would certainly make sense that the light would come on since it (the alarm) is connected to the door ajar switches.

Mine doesn't (I know that it doesn't) but the alarm works, including the hood and the door ajar works on both doors
So now I've got to start tracing something somewhere.

OZvette72

But the door ajar switches don't turn any lights on.
The door ajar switches + hood switch are triggers for the alarm and that's all.(note! ... all three are also the same part number)
For my own piece of mind I did a test and it is as follows (notice separate wire going to the hood off the main loom):-

CanadaGrant

My under hood switch controls both the alarm and the 2 foot well and 1 rear compartment lights. Not the door ajar light on the dash which is controlled by the rear switches. In 69 the alarm was an option so that might have something to do with it. I could never figure out why anyone would want the interior lights to come on when the hood was opened so maybe it was changed in later years. It's also a real pain when working under the hood as there is a constant battery drain unless you zip tie the switch down. My alarm works perfectly but I leave a zip tie on the under hood switch because of the lights.

OZvette72

I feel your pain my friend, I bought a '72, built September '71 and I reference the '73 wiring diagram. (because my ajar switch wires are Lt.Blue, White and Black).
Regards Allan

OZvette72

Just to add, when the car is started and doors or hood are ajar it will be visible by a red door ajar warning light on the center console instrument cluster above the gauges.

65GGvert

Just verified on my 72, all stock. When the key is off and the door opened, courtesy lights come on. Hood open, nothing. When key is in run position, door opened OR hood opened, door ajar lights up on dash, courtesy lights do not come on. When driving, if I pop the hood, the door ajar light comes on and stays until I close the hood or turn off the switch. Hood switch does not affect the courtesy lights at all.

EDIT: See later posts, door ajar light should NOT come on when hood opened and ignition on. It was designed to be theft alarm only. Mine was miswired by an op.

OZvette72

Hi 65GG, Mine is Sept. '71 build and yours?
It would be safe to say this is standard for all '72 models or is the AIM likely to differ?
Regards Allan

65GGvert

Nov 15, 71. I think they were pretty much standard in 72. I didn't look at the aim, because I like that it works this way. It lets me know if I forgot to latch the hood.

OZvette72

Sorry! .. let me rephrase that, what seems to happen when you think you got it right somebody comes up with a different AIM for the car you thought was right. You will be happy to know that our cars are as per the AIM.

CanadaGrant

I checked mine again today and it seems like they changed things quite a bit. The alarm in my 69 was optional so the wiring was an ad on. The rear door ajar switches were for door ajar only and controlled the dash light only. The front courtesy light switches and under hood switch are on the same circuit and control the courtesy lights, key warning buzzer and alarm. I can see now why they changed it. If you were going down the road at night, hit a pothole and one of your hood catches popped up, you would have all the courtesy lights inside come on instead of the door ajar light on the dash. The door ajar light is only controlled by the two rear door switches and that is all the two rear switches control. Nobody was thinking right in 69....

OZvette72

It's a good feeling making it RIGHT, and thanks for reminding me about the buzzer 'cause it's not right and I have completely forgotten about it. (my next job)

65GGvert

I thought I'd bring this back up due to new information. It turns out that someone had soldered my door ajar switch wire (blue) to the alarm switch wire (white) on the passenger door. When I fixed the alarm and corrected the wiring, the hood switch DOES NOT activate the door ajar switch, only the theft alarm. By changing the wiring, an OP had shorted the two circuits together which was fine until you set the alarm, then the door ajar light would come on even with the doors closed (and key off, which it never should do) , and the alarm didn't work properly either. The hood switch only has two contacts, and when correctly wired, only activates the alarm.
I don't see why, if you wanted the hood to light the door ajar switch and the alarm, you couldn't replace the hood switch with one of the door switches with the three contact set up to operate both the door ajar and the alarm, like the door switches do. You would have to run a wire from the blue wire circuit in the door ajar circuit to the extra contact on the new switch. Here is Willcox's diagram, I colored the door ajar wire blue and added a note "door ajar". You can see that there is no door ajar wire to the hood switch when stock. That blue wire connects to one side of the door ajar light in the dash.

OZvette72

Hi 65,
WOW ... too much Ajar, my little brain got lost.
Why are you referencing the '68-'70 wiring diagram when you have '72?? That diagram is showing the Jamb Switches wiring which have the alarm incorporated in it and was an option back then. Our '72 have standard alarm and the additional Ajar Switches located on the rear wheel arc as you get in (the ones you get your clothes caught on).
I have Lt Blue, Black and White wires on both Ajar Switches. ... ??? ... the Hood Switch activates the Alarm Only (no key in ignition) as per earlier diagram. (REMOVED THIS BIT as I was in PIXIE LAND)

65GGvert

If it does, it shouldn't. Mine did and someone had shorted the two wires together and soldered. If you look at the diagram, there is no connection with the ajar light and the hood switch. The hood switch has only two wires, one for alarm and one for ground. The rear of the door switch has three, one for alarm, one for ajar, and ground. If your hood switch has three wires, someone has modified it to get those results. What tipped me off on mine was when I armed the alarm, the door ajar light would come on with no key in ignition and stay on even with door closed. After following wiring and finding the short, all is well. When the two wires (blue and white), you'll read about 5 ohms on the white alarm circuit. If that happens and the alarm goes off, the flasher will cause the alarm to be very very rapidly. It will sound like a rumble instead of horn.

65GGvert

My 72 alarm system is wired exactly like the diagram (with my addition of the blue connection in the door jamb). If you have three wires on your hood switch, then you should be all set, but you can't just short the two grounds together and get both circuits to work. If yours works well like it is, you should be good to go.

PS, my door jamb switches have a black wire also for ground, and the hood switch has a black and white only,I don't see that in yours, so maybe yours is wired differently than mine.

Here is the 72 alarm diagram, you can see it's identical. I used the other because it was color coded, but this is the one I used to troubleshoot mine.