Builds Won a '74 40 on a coin toss... (1 Viewer)

[ginmtb]

What's the voltage on the output of your relay when you press the horn button, with the horns connected? When you say no voltage downstream, is that at the horns or at the relay?

The sparking is strange, the relay shouldn't be drawing that much power on the trigger wire. Just a wild guess, but maybe the S terminal has some minor short and drawing too much power and dropping too much voltage for horns to work. I've had strange things like that happen, where the voltage looked fine with no load but dropped too much under load.

Basically I unplugged the horn and put my meter in the plug and then ground to the battery and there is no voltage reading. Having done the jump test above and confirmed a working horn and relay it isn’t the ground at the horn. I think I’m going to run a ground from the steering wheel directly to the battery to again try and isolate things. While I did clean up the grounds at the steering wheel who knows if they are good. Also I wonder if during my insulation job on the firewall I damaged the wire or unplugged something... thank you for the feedback!

 

[ginmtb]

More troubleshooting tonight... frustration is mounting so I’m stepping away. Removed the assembly under the steering wheel (turn signal lever) and beeped out the horn wires. So those are fine. Cleaned up the contacts on the horn harness as I saw some corrosion there. No change still only clicking from the relay. Grounded the steering column separately just in case the rag joint wire broke or the ground is bad. Still nothing. Done for the night before I break something.

Will run some jumpers to test continuity from the horn harness plug to the relay. If that doesn’t tell me something I’m lost... then it may be just running new wires for the horn - would’ve saved a ton of time and frustration had I just done that...

 

[algeeba]

Did you ground the steering column or the shaft? I believe the column is isolated from the shaft and so the ground has to be on the shaft (which connects to the rag joint).

 

[Dudleyfj40]

The way it works is you are completing the circuit at the steering wheel buttons. The spark proves you have 12V and your steering wheel is grounded.

I would guess you have the wrong relay or it is wired wrong.

 

[ginmtb]

Did you ground the steering column or the shaft? I believe the column is isolated from the shaft and so the ground has to be on the shaft (which connects to the rag joint).

I connected to the rag joint but I really should just take the time to move the steering column back, take it out and inspect it fully. Thanks!

 

[ginmtb]

The way it works is you are completing the circuit at the steering wheel buttons. The spark proves you have 12V and your steering wheel is grounded.

I would guess you have the wrong relay or it is wired wrong.

Thanks I remember reading about completing the circuit but didn't realize the spark is okay. Guess since I've never had the steering wheel apart I would've never known.

As for the relay, my horn used to work perfectly fine. I did the Coolerman test (basically direct wired it from the battery and grounded it to complete the circuit cause the horn to work) and it worked as it was supposed to - which leads me to believe that there is something wrong with the wire between the steering wheel and relay. The continuity test should help clear that up... Hopefully!

 

[ginmtb]

Been looking at wiring schematics and noticed something interesting... The plot thickens. Appears my GR and GY wires are flip flopped. Very strange that it has been working all this time until recently. I will have to try and flip flop the wires to see if that makes any difference. @Dudleyfj40 your comment on being wired wrong looks correct! Still doesn't explain how it has worked all this time. Hopefully changing them to how they're supposed to be will work! Keeping fingers crossed.

 

[powthief19]

Been looking at wiring schematics and noticed something interesting... The plot thickens. Appears my GR and GY wires are flip flopped. Very strange that it has been working all this time until recently. I will have to try and flip flop the wires to see if that makes any difference. @Dudleyfj40 your comment on being wired wrong looks correct! Still doesn't explain how it has worked all this time. Hopefully changing them to how they're supposed to be will work! Keeping fingers crossed.

View attachment 1595499

The elf on the shelf got into your rig and switched up the wiring... been happening around here too.

 

[ginmtb]

Well just snuck out and ran jumpers so the wiring would be correct. Drum roll...

No change.

 

[ducktapeguy]

When you say you beeped out the horn wires, does that mean everything up to the switch works?

 

[ginmtb]

When you say you beeped out the horn wires, does that mean everything up to the switch works?

I beeped out the portion of the harness to where it plugs into the main harness - only about an 18" run if that. So I still need to go from that end point to the relay.

 

[thebigredrocker]

Is it possible with the sum of the parts, you still have too much resistance? If you haven’t done so, might not hurt to remove the female spades. Check the crimps and scuff away. You could open the crimps up if the wire looks oxidized or corroded, cut a 1/4” off and re-attach spade to fresh copper. Use a small pick for that.

I ground a small screwdriver down to remove spades. The trick is to push the spade into the plug as you insert the release tool. If you just insert the tool, it will push the spade backwards and the lock tab catches in the plastic slot.

 

[ginmtb]

Decided to table the horn for the time being and get back to driving it. New OEM alternator installed - thanks @orangefj45 looks beautiful and certainly will be more reliable than what I installed previously. Good thing I didn’t try to install this when I was frustrated as I may have missed the slight differences in the letters on the plug. Installed fresh new connections and rubber boot thanks to @Coolerman!

 

[Dudleyfj40]

Thanks I remember reading about completing the circuit but didn't realize the spark is okay. Guess since I've never had the steering wheel apart I would've never known.

The buttons grounds the relay, then the relay grounds the horns.

 

[ginmtb]

I decided to get a new relay, figured if nothing else I’d have a backup - thanks @Racer65! Sounds like the availability of even this aftermarket version is nearing extinction. Swapped the wires so they are correct (thanks @thebigredrocker for the tip). Cleaned the connections up some, hit the horn button, and...

Clickity click.

Okay done trying to figure this out in 2017. It will be a project for 2018 sometime.

 

[thebigredrocker]

Does your fender have a clean ground to the frame and so on? Perhaps hook a gator clip to the new relay housing and then batt -. It will be something simple.

 

[thebigredrocker]

Maybe even remove the female spades from the plastic plug and feel how snuggly they fit over the male spades of the new horn relay. Might need squish the female spades curl to tighten the fit.

 

[ginmtb]

Good idea on the separate ground for the relay. I will try that.

As far as fit they fit really tightly on there so I think that connection is good. Thanks for your support through this - nice to have other opinions and options as one struggles through issues.

 

[ginmtb]

Tried grounding the relay separately still nuttin’...

 

[gator25]

Sounds like something is shorting out, I bet its in the column. But I wouldn't bet much lol.