Ignition key warning switch

[Duane R.]

Having trouble with my 70 ignition key warning switch. Last week when the key was inserted, the horn came on whether the driver door was open or closed. However, when the key was turned to the run or start position the horn shuts off. When turning the key back to the off position the horn came on whether driver door was open or shut, it did not turn off. Only when the key was removed did the horn stop. All the wires in the switch at the driver door tested good and made solid contact with the door switch metal when the door was opened. The wires in the door switch and warning switch in the column to the horn relay were connected properly.
Yesterday I removed the steering wheel and all other parts to reach the two-pronged buzzer switch that touches the two pads on the signal switch. All parts appeared to be installed correctly and had continuity between the prongs and pads. Only thing that has not been looked at is the lock cylinder.
Any suggestions would be helpful.

[Mark E.]

Re: Ignition key warning switch

Does the horn engage or the buzzer in the horn relay?

[Duane R.]

Re: Ignition key warning switch

The horn engages

[Mark E.]

Re: Ignition key warning switch

The horn engages

Well, that's an odd electrical anomaly. This reminds me of a '73 fixer-upper I bought in my youth- the dome lights came on when the clutch was depressed. It turned out the dash harness was badly butchered by several "mechanics" looking for and repairing problems.

Are you sure it's the horn that's activated? When the key is inserted, a buzzer in the horn relay should sound, not the horn.

[Bill B.]

Re: Ignition key warning switch

Did this issue suddenly occur without previous work in the horn relay or steering column area? If so, it may be the horn relay itself. If not, could be crossed wiring (Horn button and Key warn switch).

What happens when you activate the horn at the steering wheel with the key out and doors closed?

[Edward J.]

Re: Ignition key warning switch

Duane, I know the key buzzer switch inside steering column have been known to break, just wondering if it broke and the broken piece is some how causing your problem? With age the plastic is brittle and they tend to break.

[Duane R.]

Re: Ignition key warning switch

Bill, with doors closed and key out or in the horn activates

[Duane R.]

Re: Ignition key warning switch

My error, the buzzer activates not the horn.

[Duane R.]

Re: Ignition key warning switch

Ed, all plastic items in the column appear to be solid without cracks.

[Bill B.]

Re: Ignition key warning switch

Duane,

Just for clarity, if you "beep the horn" using the center button, the buzzer sounds. If you keep the key in the ignition and open the door, the horn sounds.

If this is the case, then it appears the two black push-on spade connectors (one has a pink wire with black stripe, the other a solid black wire) may be interchanged at the horn relay. Let me do some more digging before you attempt to reverse them.

[Bill B.]

Re: Ignition key warning switch

OK, here is a pic of the horn relay connections underneath the relay. You can see the positions of the red (with black stripe) wire and the black wire. (I took these several years ago during my rebuild so I would have a record of the orientation if I forgot which went where. Hope these help.

Horn Relay.jpg

Horn Relay II.jpg

The green wire with the white terminal goes to the horns (two on 1970, just a single horn subsequent)

[Duane R.]

Re: Ignition key warning switch

Bill, thanks for the photos. They are in the same alignment as mine and in the AIM diagram. Evidently it is more probable that the problem is coming from the column. Most likely it is with the bezzer switch or the key cylinder.

To clear up the noise issue, the horn is engaged "only" when the steering wheel center button is pushed and "never" when the key is in the cylinder. The buzzer engages "only" when the key is in the cylinder and "does not" silence until the battery is disengaged. Opening the driver side door does not silence the buzzer either.