acloud

(on a 73 Cutlass)
3 wires: 1 green, 1 Black, & 1 pink(I think)
They all have single plugs on the ends.
I am going to assume the PINK should be the seperate single plug.
There should be a Plug with 2 wires (based on the Relay)
One would be the green wire and one would be the Black wire, , ,
But which Wire goes to which Terminal.
With the relay mounted on the firewall 1 wire is close to the firewall and the other is inline with it but farther from the fire wall. When I unplugged the single plugs, the black wire was closest to the firewall.
I need to know the correct wiring before I hook up the NEW Relay so I dont Fry it.
Thanks in advance,
Andy
I Pic of how somones would be great !

Lady72nRob71

Your photoshopped-in wire color locations are correct! Black in the back, green on the front and pink on the drivers side. I confirmed with mine...

MDchanic

The shapes of the original plugs are different to make misconnection impossible - notice how the terminal insulator you labeled green has a little "teat" on it that the other terminal doesn't have.

Also, in case of confusion, the terminals are numbered, and those numbers should correspond to numbers on the schematic in the Chassis Service Manual.

- Eric

acloud

The way I drew the colors is the way I found it. It appears the relay is Kaput! I ordered a new one today and it's supposed to be at the parts store tomorrow (Saturday). . . Since it is shot I didn't know if it was because it had been wired wrong. Everything on this car so far was either cut, hacked or rigged. It been a struggle to get things wired and working as they should.
I'll check the Numbering on the terminals and compare it to the Service manual.
I looked at the manual earlier today but didn't notice the terminals being numbered and I don't have the Old relay out yet since I still needed the junction part inatact.
Remind me to disconect the battery before swapping the Relay (note to self).
Thanks guys,
Andy

MDchanic

Looks like I was wrong - the manual doesn't have one of those little plug diagrams for the horn relay, but it does show that the black wire is from the horn button and the green wire is to the horns. Connect the black wire first, and see if the relay clicks when you push the button - if it does, you've got it right.



Oh, and don't forget to disconnect the battery!

- Eric

acloud

After my Heat /AC wiring (well, actually during) I found and bought a 73 Service manual on ePray. It has the same (or similar) wiring diagram in it. In the back back I found a sketch of the relay WITH the terminals Numbered. In the pic of the new relay I can see that there are #'s . I'm on my way to get the relay now. I'll let ya know how it works out.
Andy

Lady72nRob71

Just giving an Extra reminder!
That 1/4" stud and nut are hot 12V with key on or off. The main supply wire from the battery is NOT fused, so a short from that one would be very bad.

acloud

For future Reference

MDchanic

THERE'S the one with the numbers!

Thanks, Ace!

- Eric

acloud

So far everything has been a success ! Installed Horn relay, rewired Blower Relay with new plug, re-routed some wiring and stuffed most of it into wire looms and zip-tied stuff in place. I just need to re-assemble the horn pad/button and install it.
Woohoo ! (oh, Ithink its a 75-76 steering wheel and horn pad).
I was thinking of offering the guy who runs Wildabout cars.com to scan sections of my service manual so he can post '73 info on his site. He currently has no '73 info.
Andy

Goldhawg

Thread from the dead! Need some help. I rewired my car, and everything worked...except for the horn. I found I had reversed the two connectors. But I may have another issue, on my relay the terminal that supports the black lead is 12v all the time. Is it supposed to be that way? Cuz then I have 12v up on my horn contact in my column!

MDchanic

The wire to the steering column completes the circuit when the switch in the horn button makes contact with ground, so, yes, that wire will check out as hot.

- Eric

Goldhawg

Hmmm...well that's good. So I go out and (I've got the steering wheel off) touch the horn contact button to the center of the column to ground it and the horn doesn't go off. Should I be able to make the horn work this way?

I do here some noise under the dash when I do this (not out under the hood at the relay). Not sure what that is.

EDIT: noise (minor popping) comes from the fuse block when I connect the 12V to the column.

oldcutlass

The black wire in the column is the negative feed to the horn relay which has 12v at the coil from the junction block. So measuring voltage from the black wire to ground will show 12v as Eric said. When you touch that wire to ground you are activating the horn relay and that should have fed 12v to the horn. That is probably the sound you hear. I would suspect your missing the 12v between the relay and the horn.

Goldhawg

Are you saying the relay doesn't work? It is a new replacement relay, but that doesn't mean it wasn't DOA. Is there any other way to test the relay?

oldcutlass

I'm saying that the noise you hear is the relay clicking on and off. The relay is always connected to 12v and is looking for a ground to activate. Check the wire from the relay to the horns by connecting it to 12v and see if the horns are working. If the horns work then for some reason your relay is not providing the 12v through the contacts when the relay activates.

Goldhawg

the horns definitely work; when I had the leads reversed every time I tried to plug in the horn lead it let me know!

oldcutlass

Which lead is causing this, at the steering wheel, or at the relay?

Goldhawg

Well, I put on the old relay, still no joy. Then I took the 12v lead on the relay (the black wire in first post above), and I took a wire to the battery ground and then the horn blows. I take the same wire to the end of the contact on the horn and connect it to my ground cable going to the battery (just checking if I wasn't getting a good enough ground in the steering column) and I get no horn--just the small electrical arc when I touch the ground to the 12v, and some popping/clicking noise coming out of the fuse box. I connected my meter to the end of the black line at the horn relay, and the other to the contact point in the wheel and it reads ~75 ohms.

I should say that this a completely new 18 circuit wiring harness that I put in; this seems to be the only thing that may not be right. And I don't know the condition of the wiring in the 40+year old tilt column.

Thoughts?

MDchanic

If you can blow the horn by grounding the horn relay wire, then the relay's good and the horn is good.

Next is to figure out why the wire through the column won't blow the horn.

I'd ground the column wire to a solid ground on the upper end, and then test resistance between the contact on the lower end that's supposed to go to the relay, and ground.
Should be zero ohms.
If you've got resistance, then there is a bad connection in that wire, starting with the plug that goes to the relay.

If you have no resistance in that wire, the next thing to do is check resistance between the steering wheel and a good ground.
Should be zero ohms.
If you have a few ohms, that means that the steering wheel / column isn't properly grounded. First thing to do is make a jumper across the two sides of the rag joint.

- Eric

Goldhawg

OK, did this, and I had zero ohms.

Did this, and meter read .3 ohms (which I thought was low enough to mean a good ground).

Any thoughts on the 75 Ohm resistance between the line at the horn relay back up to the horn contact? Does that tell me there is a problem in that line?

oldcutlass

Use a jumper wire from the top of the steering shaft ground, bypassing the wire in the column, to the negative coil terminal on the relay and see if the horn works. If it does, then that wire is open.

Goldhawg

Mystery solved...thx for all your help. Turns out the popping noise was the HORN relay that came included in my aftermarket wiring harness fuse box. I did not need to be using the stock horn relay. As soon as I unplugged both lines to the stock horn relay under the hood and ran a jumper wire across, then went inside and turned the key on, when I then grounded the horn contact it worked, and yes since the door was open it started buzzing too. So now a little clean up but I will permanently bypass the horn relay and put my steering wheel on.

Thx again...very patient and helpful.

oldcutlass

Glad your got it fixed. Aftermarket harnesses, pffffffft, lol.