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Jean-Marc Dugas
03-26-2013, 07:53 AM
I am in the process of wiring my new B&M Super Chief. All is going well, except that I cannot make it work......

The siren works fine by itself, the problem is that the steering wheel horn switch is not working anymore. I did not cut any of the Pontiac wires since they were already spiced from a previous installation.

Last night I was trying to follow Pontiac's troubleshooting guide for horn issues, but the problem is that I am not sure which one of these two relays is for the horn.

If someone could identify which one should be the horn relay, and what is the other relay is for that would be a great help.

Thanks



http://www.professionalcarsociety.org/forums/picture.php?albumid=5&pictureid=2498

Russ Austin
03-26-2013, 09:13 AM
Check for power on both. The relay should complete the ground, but not sure on your Pontiac. Check to see what relay is grounding when the horn button is pressed.

Jean-Marc Dugas
03-26-2013, 09:57 AM
Thanks Russ.

I was talking with a friend of mine that had a 69 Bonneville. He thought that the horn relay (on the 69) was close to the front clip, not the firewall.

For some reason the Pontiac Service manual has no drawings of the horn wiring system. It seems to have everything but....

John ED Renstrom
03-26-2013, 12:13 PM
you may be forced to do the sparks fly method. but my experience with GM is the relay is usually next to the components. the blower over by the blower that kind of thing. the horn relay is normal on the left fender about half way up on in the inside of the radiator support on the left.

but first before you tear to much stuff apart. stop and think. did everything work before you changed the siren? if it did then it was something you did changing the siren. not one of the other components.

the horn siren switch just moves the ground wire from the siren relay to the horn relay. they did it with a double pole single throw switch spliced into the horn relay ground wire going up the steering column.

superior was big on the crimped splices and did not care were then put them. this make tracing out a circet in them a mystery.

so start with did it work before? what did I just do that changed things?

quick test is at the horn siren switch can I ground out either side and get the device to work. ground one side the horn should honk the other the siren wail. if they do your good from there forward and the problem is in the switch or your connection to the ground wire going to the horn button.

if the siren gos and horn doesn't then go to the horn make sure it's connected and it works. then work you way back to the switch. you'll find that relay in between. seen it happen more then once that messing around up front, you knocked off the wire to one of the horns and thats were your trouble lies.

the key is to start from somewhere and work your way to some were before going off in another direction.

but to answer your question the right one is most likely the high fan the center one the relay for low and intermediate. right about here GM used one on both sides. the relay your looking for would only have 3 wires to it one hot, one out to the horn, the other back to the horn button. it should be small and black.

Paul Steinberg
03-26-2013, 12:20 PM
The horn relay is usually mounted on the radiator core support near the voltage regulator, or on the firewall. In your car, according to the 1968 Pontiac shop manual, the horn relay is also the warning buzzer, so if you leave the key in the ignition, and open the door, the buzzer should start alarming. That is one way to identify it, assuming that Pontiac used the same wiring schematic in 1969 as they did in 1968. Looking at your picture, I am going to go with relay #2, as being the horn relay. The other relay appears to have screw terminals on it, and the factory horn relay would have used a push on terminals mounted in a single plastic insulator. In all probability, it will have a single red wire that comes from the battery positive terminal or the positive terminal of the voltage regulator, and then a 3 wire connector with a black wire, a black wire with a pink tracer stripe, and a dark green wire. The red wire is a constant hot, and the black wire goes to the horns, The dark green and the black with pink tracer are trigger wires, one going to the horn contact, and the other going to the ignition switch. One of these two wires will be the ground wire from the horn button on the steering wheel, and the other will be a hot wire only when the key is in the ignition in the off position, and the drivers door is opened. This is assuming that it wasn't disabled by a previous owner. What the other relay is for, I have can only guess at. Possibly a heater blower relay?

Paul Steinberg
03-26-2013, 12:36 PM
I have just looked at your picture again, and I can see that there is a circuit breaker mounted on top of relay 1, and I can't see the wiring on relay 2, but it appears that the wiring is coming from the passenger side of the car to that "devise". I am not certain exactly what these metal cans actually are, since the picture is taken at a distance, and it isn't that sharply focused. GM wired the relay from the bottom, and since those two devices appear to be side wired, I am thinking that they are something that was either altered from the original factory wiring, or was added by Superior Coach. Below is a picture of a new horn relay for a 1969, 1970, Pontiac New Horn Relay GM Pontiac GTO 1969 1970 relay.

Joe Rackov
03-26-2013, 09:01 PM
To the left of the radiator on the core support facing inboard. Upper side near the top of the core support. I have a '67 shop manual for diagnosis and wiring diagrams if you need copies.

I don't have a current parts catalog at home, I do at work. Possibly the relay may still be available from GM, stranger things have happened.

PM me if you need more info.

Joe Rackov
03-26-2013, 09:12 PM
I looked at the photo you posted and have to concur with Paul that those relays don't seem to be O.E. Being that your car is a non factory A/C car there is no factory installed reason for the relays. Non A/C big Pontiacs did not use relays for blower motor control, it went through the heater control and blower motor resistor. IIRC this did not change until the early 1970's.

Either Superior or someone later added these for another reason.

John ED Renstrom
03-26-2013, 10:44 PM
I am in the process of wiring my new B&M Super Chief. All is going well, except that I cannot make it work......

The siren works fine by itself, the problem is that the steering wheel horn switch is not working anymore. I did not cut any of the Pontiac wires since they were already spiced from a previous installation.

Last night I was trying to follow Pontiac's troubleshooting guide for horn issues, but the problem is that I am not sure which one of these two relays is for the horn.

If someone could identify which one should be the horn relay, and what is the other relay is for that would be a great help.

Thanks



http://www.professionalcarsociety.org/forums/picture.php?albumid=5&pictureid=2498

with out being there to see one could be the added relay from superior for the rear coach lights, heater fan ext. but defiantly neither is the horn relay. were is the solenoid for the siren? does the car only have the horn /siren switch or is there a direct button for it also? does the horn toot? the horn relay has nothing to do with the operation of the siren.here is a wiring diagram for the B&M. in your case were the floor switch is located would be the horn siren switch then the horn button would ground it. move the horn/ siren switch the other way and the siren is out of the circuit. be sure that you get the brake hooked up right for the B&M if yours has one

Jean-Marc Dugas
03-27-2013, 11:07 AM
I did find the relay, and it is at the front by the radiator.

As far as the wiring goes, I am following the wiring diagram that came with the siren. The sires/horn are wired through a on-on toggle switch which lets me pick either the horn or the siren. I did not have to cut any wires because there was already a switch in placefor the previous set-up.

And the horn was working before I started this little project. As usual, I have the habbit of creating problems when I touch something with this car.....:bonk:

I think that I must have pulled a wire somewhere that renders the horn switch on the steering wheel not to work, unless if there is a fuse somewhere in the horn circuit.

John ED Renstrom
03-27-2013, 11:57 AM
can you honk the horn from the relay? ground the lead that goes back to the firewall. it should honk. all you are trying to do is determine were the problem is. if you can't get them to work from the relay. then touch each horn with 12 volts and see if they honk. you may have just lost the ground for them putting the siren on. if you haven't taken the switch out to have a problem under the dash would be strange. so if I'm understanding you correct the siren now works as it should the horn does not. you haven't taken anything apart inside the car?

your simple test it, if I put 12 volts to the horn does it honk? yes they are good. no check ground of radiator support. if I ground the relay out does it honk the horn? if no then check your connections. do you have 12 volts to the relay? if yes and grounding the relay doesn't give you 12 volts out then replace the relay. but if you ground the relay and it clicks you get 12 volts out but the horn doesn't honk. check the wire going to the horn. of course finding the relay was the first step. here s a crude sketch of how they should be wired.

Joe Rackov
03-27-2013, 04:27 PM
IIRC your car is a '67, right?

The horn relay part number was 1116920 but it has been discontinued by GM. The catalog shows usage for 66 to 67 model years.
You may be able to get one at NAPA.

Jean-Marc Dugas
03-27-2013, 09:46 PM
Thanks for all of the advice. Here is what I did so far.

I work my way backwards fron the horns and the siren. Both work well. Then I tested the relays, they both work as they are supposed to.

I changed the horn/siren switch, just in case, no change. The only two itwms left are the steering wheel horn switch and the half moon connector under the steering colum. Using the test light t the half moon connector, nothing comming from the steering wheel side, so the problem is between the steering wheel and the connector.

Took the steering wheel centre out and unscrewed the steering wheel spoke cover to expose the actual switch. Tested the circuit with the test light, and the test light lights-up atthe connector site.

The problem must then be between where the wires comes out of the horn switch and disapear into the steering wheel column.

John ED Renstrom
03-27-2013, 10:22 PM
are you showing power under the horn ring? ground it to the nut in the center of the wheel and see what happens. if you have power there the circet is good you just not grounding when you press the horn ring

Kevin O'Connell
03-29-2013, 07:44 AM
Jean-Marc, Brian should have enclosed the wiring diagram for use with a horn/siren switch with your siren. The circuit requires a double pole double throw switch. It can also be used with a floor button. Let me know if that diagram wasn't included.

Jean-Marc Dugas
04-06-2013, 08:13 PM
I finally had time to get back to this problem this afternoon. I pulled the steering wheel so I could have access to the ring (that is located on the steering wheel and connected to both horn buttons) and the plunger connector that is part of the steering column.

When I ground the connector that comes out of the steering column, both the siren and horn work. When I test the steering wheel circuit everything works like it should while the steering wheel is on the bench.

Next I used alligator clamps to simulate the complete circuit as if the steering wheel was back on the column, and everything worked. I also cleaned all of the contact surface, tested everything again and all was working well.

I proceded to put everything back together, and nothing. Took everything apart again tested everything, put it all back and still nothing.

Paul Steinberg
04-06-2013, 09:45 PM
Either something is missing or you have something installed up side down. Post a close up picture of the steering wheel and horn parts, and possibly I can figure it out.

John ED Renstrom
04-06-2013, 11:14 PM
broken or weak spring on the contact. the wiper has to be touching the slip ring or it will not make contact.

Jean-Marc Dugas
04-07-2013, 10:26 AM
Finally success:applause:

Put everything back in place this morning and voila!! Both the horn and the Super Chief are working.

Next project........the Amp meter........

John ED Renstrom
04-07-2013, 11:17 AM
you know in my years of playing around I have found that if you put all the parts back in it usually works. I been known to take a couple 3-4 swipes at it a time or two.