Author Topic: Turn signal and Horn conundrum  (Read 1502 times)

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Turn signal and Horn conundrum
« on: November 29, 2020, 10:39:32 AM »
Hey all,
I recently replaced the ignition tumbler in my 78 c15. While I had the column apart I replaced the turn signal cam. Now that everything is back together my turn signals don’t work, and my horn doesn’t sound, but I can hear the relay clicking. To make this slightly more puzzling, my hazard switch works. Everything used to work before I did this little project.

Basically my question is, is there something that would interrupt power going from the horn relay to the horns themselves that may also be connected to the turn signals? Also, I did replace the 15A fuse for the turn signals.

Thanks everyone!

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6454
Re: Turn signal and Horn conundrum
« Reply #1 on: November 29, 2020, 11:12:26 AM »
Did you by any chance remove the turn signal flasher and forget to reinstall it in the fuse box?  If you hear the horn relay clicking the problem is somewhere between the relay, the horn, and the horn ground.  Have an assistant press the horn button while you use a test light or voltmeter to check for power on the green wire that connects to the horn.  If you detect power at the horn, then either the wire connection to the horn needs cleaning, the horn ground needs cleaning, or the horn is faulty.  If there is no power to the horn, try unplugging and replugging the horn relay.  Rarely, the relay itself will fail.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Re: Turn signal and Horn conundrum
« Reply #2 on: November 29, 2020, 11:17:31 AM »
The turn signal flasher, I assume is the round electrical component that I have hanging under the dash with, I believe a purple and a black wire running to it. I didn’t touch that during this project. I did happen to replace the horn relay earlier, just in case and to rule it out.

Could the flasher be the culprit even though the hazard is working?

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Re: Turn signal and Horn conundrum
« Reply #3 on: November 29, 2020, 11:35:58 AM »
For reference,  pic of my fuse block, and the turn signal relay... which may be my hazard relay... or the same thing.. I’m not sure

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6454
Re: Turn signal and Horn conundrum
« Reply #4 on: November 29, 2020, 12:37:34 PM »
The item you are calling a "turn signal relay" is more commonly known as a "turn signal flasher" or simply "flasher."  The turn signals and the hazard lamps rely on separate flashers to function.  The hazard flasher is plugged into the top left corner of the fuse box.  The turn flasher, as imaged, is free-hanging.  The two flashers are interchangeable, so try switching them and see what happens.  If the turn flashers still don't work after switching the flashers, check the 15-amp "DIR. SIG." fuse and it's socket connections in the fuse box.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Re: Turn signal and Horn conundrum
« Reply #5 on: November 29, 2020, 01:14:22 PM »
Bd, thank you so much for your help so far. I now can use the turn signals with the power on, which may have always been the case, but further tinkering got me there.

However, my horn doesn’t work still. If I ground the wire to the steering column, I get a tiny spark and I can hear the relay closing. So I am assuming I need to chase down power from the relay to the horn. Is that about right? Thanks again for getting me this far!

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Re: Turn signal and Horn conundrum
« Reply #6 on: November 29, 2020, 02:37:02 PM »
I suppose, I hadn’t considered that my horn has gone bad.

If I unplug the first horn (drivers side) will the other horn still sound, assuming my button and all wiring prior to the first horn are working properly, or do I need to make a small “jump” in the connector? The horns are only about 5 years old, which is why I’m a little skeptical.

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19020
Re: Turn signal and Horn conundrum
« Reply #7 on: November 29, 2020, 06:05:17 PM »
Don't assume age has anything to do with faulty components especially if they are aftermarket. As BD said
Quote
If you detect power at the horn, then either the wire connection to the horn needs cleaning, the horn ground needs cleaning, or the horn is faulty.
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Ben_Greenberg

  • Registered Users
  • *
  • Posts: 124
Re: Turn signal and Horn conundrum
« Reply #8 on: November 29, 2020, 06:33:26 PM »
Thanks y’all! I’m gonna check the horns later this week and report back!