75 Alarm issue
Thread Starter
Instructor
Joined: Sep 2010
Posts: 111
Likes: 4
From: Grosse Pointe Michigan
75 Alarm issue
Alarm sounds when key switch is activated. Button on the key switch is depressed and is functioning, the hood ajar switch is functioning properly, doors are closed and functioning (as far a I can tell because door ajar light comes on when open & off when closed). Replaced flasher and relay, removed horn and cleaned ground and all terminals, horn works fine.
Question 1- should door ajar light come on when hood is open?
Question 2 - Were do I look for alarm issue?
Question 1- should door ajar light come on when hood is open?
Question 2 - Were do I look for alarm issue?
Race Director
Joined: May 2006
Posts: 18,731
Likes: 2,582
What do you mean by key switch and the key switch is depressed?
Are you referring to the switch on the fender?
Is this the factory system or something aftermarket?
the hood does not trigger the door ajar
Are you referring to the switch on the fender?
Is this the factory system or something aftermarket?
the hood does not trigger the door ajar
Last edited by MelWff; May 20, 2020 at 02:36 PM.
Thread Starter
Instructor
Joined: Sep 2010
Posts: 111
Likes: 4
From: Grosse Pointe Michigan
Key switch on front fender. The anti theft switch behind the Key cylinder Is adjusted so the button is pressed in. This is the factory alarm system. The fact that the hood switch does not trigger the alarm clears up that point. Do you have any idea on what might be triggering the alarm as soon as the key is turned in the fender lock?
Race Director
Joined: May 2006
Posts: 18,731
Likes: 2,582
Disconnect the wires connected to the hood switch and turn on the switch, does the alarm still go off?
If it does, note the door switch adjustments and remove and disconnect one at a time and recheck the switch in the on position.
Still goes off check the relay.
If it does, note the door switch adjustments and remove and disconnect one at a time and recheck the switch in the on position.
Still goes off check the relay.
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
How did you test that the hood pin switch is functioning properly?
It is not connected to the door ajar light in cabin.
Remove the wires from the hood switch and arm the system again.
You said you replaced flasher, does the alarm now pulse or is it constant?
One thing to remember is that these swithces are all "set" by how much the hood or door closes. If you ever repalce the weatherstrip then you better get new switches because the plunger will not go in as far as it used to. Alarm will sound.
It is not connected to the door ajar light in cabin.
Remove the wires from the hood switch and arm the system again.
You said you replaced flasher, does the alarm now pulse or is it constant?
One thing to remember is that these swithces are all "set" by how much the hood or door closes. If you ever repalce the weatherstrip then you better get new switches because the plunger will not go in as far as it used to. Alarm will sound.
Thread Starter
Instructor
Joined: Sep 2010
Posts: 111
Likes: 4
From: Grosse Pointe Michigan
It was a new switch so I put a several layers of masking tape on bottom of the hood and coated the top of the switch pin with black marker, closed the hood and got a good depression on tape pad. Also tested the ground to it and power to the other wire.
The alarm pulse’s and sounds strong.
if the door ajar Light works for each door wouldn’t that mean the alarm would also be working because it works off of the same switch?
The alarm pulse’s and sounds strong.
if the door ajar Light works for each door wouldn’t that mean the alarm would also be working because it works off of the same switch?
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Yes for the door switches and flasher.
But did you try disconnecting the wires from the hood switch?
The problem I see with putting tape on the hood to "get a good depression" is that when you remove the tape the switch plunger will not be at the same height. Might be at the hairy edige of making electrical contact.
This is the same as having old compressed weatherstipping anf the switches work correctly. Then you put on new weatherstrip and the door does not close as far now, and the switches never make conctact.
But did you try disconnecting the wires from the hood switch?
The problem I see with putting tape on the hood to "get a good depression" is that when you remove the tape the switch plunger will not be at the same height. Might be at the hairy edige of making electrical contact.
This is the same as having old compressed weatherstipping anf the switches work correctly. Then you put on new weatherstrip and the door does not close as far now, and the switches never make conctact.
Last edited by KenSny; May 22, 2020 at 07:36 AM.
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