air horn install question

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=11584
Printed Date: August 27, 2025 at 9:52 PM

Topic: air horn install question

Posted By: underthegun
Subject: air horn install question
Date Posted: March 28, 2003 at 6:06 PM

Whats goin on everyone.

Today I tried to install a Wolo air horn in my 2002 grand am gt...everything went OK but when i put the inline fuse in after I was done, the horn goes off...I wired pin 85 on the relay to the positive side of my existing stock horn wire, right above the connector next to the horn, I think this might be the culprit buy I am not sure...

the wiring is as follows.

negative lead on compressor is grounded to chassis

positive lead on compressor goes to pin 87 on relay

12 v constant goes from under hood fuse box, with inline fuse, to pin 30 on relay

pin 30 on relay is then jumped over to pin 86 on relay

pin 85 is connected the the positive lead coming off of the connector on the stock horn

now when i insert the inline fuse, the horn goes off...what am i doing wrong? I want this horn to sound when I hit the OEM horn button on my steering wheel.

any help on this would be greatly appreciated.

Thank you

Replies:

Posted By: themagicone
Date Posted: March 28, 2003 at 6:59 PM

Your want to find the wire that goes to ground when you press your factory horn or switch 86 to ground.

Posted By: underthegun
Date Posted: March 28, 2003 at 7:22 PM

themagicone wrote:

Your want to find the wire that goes to ground when you press your factory horn or switch 86 to ground.

thank you for the reply, but could you explain a little more? Do you mean to change the jumped pins(86 and 30) to ground? And should I ground it to the stock horns ground or the chassis? Thanks

Posted By: themagicone
Date Posted: March 28, 2003 at 7:52 PM

HORN TRIGGER|black |- |steering column

                       87 - To 12vlt input of air horn
85 12vlts      87a N/C           86 Black horn input
                      30 12vlts constance

Posted By: auex
Date Posted: March 29, 2003 at 8:36 AM

Okay, it sounds like you are doing this under the hood. For the basics you need to wire the ground of the air compressor to the chassis, the power for the compressor to 87 of the relay, 30 will be +12V, and as for 85 this will go to the trigger for the horn,86 will be the opposite of the trigger( if the trigger is negative or ground then 86 needs to be +12V, if the trigger is +12V then 86 needs to be ground). If you are doing the wiring under the dash then see themagicone's diagram.

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