Hello, This is my first post; my name is Bob and I an in Fort Worth, TX. I just purchased a 1979 2wd SWB GMC Sierra Grande ½ ton and I am going to have a million questions for the board members. I have attached some pics for your viewing pleasure. The guy I bought it from misrepresented so many things about the truck, I have lost count. I now have to fix them one at a time and that leads me to my first question. The horn does not work. The previous owner said it worked the “just day before but his nephews were honking it a lot and they may have blown the fuse”. Ok…..so I replaced the 20amp fuse and right away it blows. I put in a 25amp just to see and yes that blows too. I ran power directly to the horn and it works great so that is not the problem. I tried to find the horn relay but no luck; does anyone know where the heck that relay is? I was thinking that the relay may be the problem but since I am no troubleshooting genius can anyone else jump in and give me some advice? I have a Chilton’s manual but the wire diagram does not even show the horn let alone a relay for it. I have also ordered some additional manuals but have not received them yet. I appreciate any and all advice and guidance you can lend. Thank You, Bob
Well the relay should be above the fuse box for the horn it should have a big orange wire for sure but might have two more or three wires with it. Should look like rectangler shape or round shape I forget now for sure, it might be about 6" to 8" off the fuse box. The other thing it might be is a bad ground at the horn. If the kid did do that enough and it had a bad ground might have arc the relay contacts and it shorting out there now. The horn or horn's grond to the rad surport by the mounting bolt make sure it good connection there too. I hope this will help you.
