DickieBear Posted January 8 Share Posted January 8 It's 3:30 a.m. in the morning and I was awakened by the blaring sound of my 1977 Cadillac Eldorado horn. Not just a toot or two, but a full on steady horn. I jump out of bed and run out to the car, open the hood and unplug the horns to get it to stop. I have no idea why it would just go off by itself, for no reason, in the middle of the night. I didn't check the horn pad on the steering wheel yet. Does anyone have any ideas why? 👻 Link to comment Share on other sites More sharing options...
3macboys Posted January 8 Share Posted January 8 Can't help with the horn but did you disconnect the battery as well just to be safe? 1 Link to comment Share on other sites More sharing options...
8E45E Posted January 8 Share Posted January 8 Maybe the Alarm System was actually working. Any signs of 'forced entry'? Â Craig 1 Link to comment Share on other sites More sharing options...
Buick35 Posted January 8 Share Posted January 8 Dose your Eldo have a stable or garage mate? It's not unusual to feel "horny" at 3:30 in the morning,just kidding!Sorry,I couldn't resist. 3 Link to comment Share on other sites More sharing options...
TheMoneyPit Posted January 8 Share Posted January 8 While I am still chuckling at Buick35’s answer my only thought was if you had any critters in your garage? This happened to one of my modern cars and I found that a squirrel was trying out the culinary delights of my wiring… 2 Link to comment Share on other sites More sharing options...
rocketraider Posted January 8 Share Posted January 8 Does Eldorado have a factory or aftermarket alarm system? Pin switches on hood, trunk and doors can short out or even vibrate themselves into completing a ground circuit and setting off an alarm system. Â My friends who work electrical substation maintenance tell me squirrels and snakes cause most of their emergency work. You'd think that after all these years tree rats would have learned about electricity... Â Â 1 Link to comment Share on other sites More sharing options...
pfloro Posted January 8 Share Posted January 8 (edited) 28 minutes ago, rocketraider said: Does Eldorado have a factory or aftermarket alarm system? Pin switches on hood, trunk and doors can short out or even vibrate themselves into completing a ground circuit and setting off an alarm system. As rocketraider noted, an alarm pin switch or the associated wiring may have "shorted to ground" causing the horn to sound. However, the factory or aftermarket alarm systems I've worked with over the years "cycle" the horn (short honk, pause, short honk, repeat...).  If an alarm system exists, it's controller may have failed causing a continuous "energizing" of the horn... Also (alarm system or not), the little spring inside the horn relay may have broken causing the "high current" contacts to close.   I would rule out an alarm system (if present) before doing anything else...  Think like Sherlock Holmes...!  Paul Edited January 8 by pfloro (see edit history) Link to comment Share on other sites More sharing options...
thunderbird sunroof Posted January 8 Share Posted January 8 contacts. in horn pad. Â touched. Â happens on this model. 77-79. cadillac. Â Â was it colder? 1 Link to comment Share on other sites More sharing options...
zepher Posted January 9 Share Posted January 9 If it was the horn pad, as thunderbird sunroof posits, then the horn relay would still be energized and can drain the battery over time. Best bet would be to pull the horn relay and reconnect the horns. Link to comment Share on other sites More sharing options...
thunderbird sunroof Posted January 9 Share Posted January 9 1 hour ago, zepher said: If it was the horn pad, as thunderbird sunroof posits, then the horn relay would still be energized and can drain the battery over time. Best bet would be to pull the horn relay and reconnect the horns. I have seen this over my cadillac career.   when it's cold. the contacts hit.  and the horn goes off.  1 Link to comment Share on other sites More sharing options...
pfloro Posted January 9 Share Posted January 9 (edited) 58 minutes ago, thunderbird sunroof said: I have seen this over my cadillac career.   when it's cold. the contacts hit.  and the horn goes off.  If this the cause, what is the fix...?  Referencing the wiring diagram segment below: Relay connection #3 powers the horns when the relay is energized. Connection #1 is always hot. Connection #2 is the relay coil. It is grounded and the coil is energized when the contacts in the steering wheel pad close.    To verify if the steering wheel pad contacts are the problem: Disconnect the relay connector. With an ohmmeter, measure the resistance from connector #2 to ground. If zero ohms, the steering wheel pad (or wiring) is the problem. If infinity, the problem is at the relay or "beyond"...  Paul    Edited January 9 by pfloro (see edit history) Link to comment Share on other sites More sharing options...
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