Packard Forum Index » Pre-War (1899-1942)

Finally got my 1940 356 engine running. New ss exhaust valves and guides, as well as, new wrist pins, bushings, new rod bearings and rings, what a job!. Thanks for the help from everyone as this was my first engine repair. The last issue now is the horn which worked before the rebuild, now it doesn't. Relay clicks, can get one horn to work sort of if hooked directly to 6volt and ground. The other horn just sort of "buzzes". Any thoughts would be appreciated.

Not entirely sure where the horns are located on a 40 but if on the head like the 47, any chance the engine rebuild has a nice coat of paint and some sealer around the head studs and other various bolts. If so I would seriously look at a ground problem. Horns need a pretty healthy amp flow so large wires and good ground are a must. A poor ground, dirty connection, and/or testing with too small a wire would result in your symptom. A poor ground might be adequate for the relay draw but not the horns. To rule that out, you could take a jumper cable and go from a good frame ground to a nice shiny place or bolt directly on the bracket or horns and see if that changes the situation.

Thanks, cleaned up ground surfaces as well as contact points inside each horn. What the problem tuns out to be is the ground wire from the bottom of the steering column to the horn ground is open somewhere. How that happened is beyond me. Gus the best option is to install a jumper wire, this wont look correct but opening up the wire harness would look worse. Any other options?

You mean bottom of steering wheel or box to horn relay don't you? There is no direct connection between horn ground and wire from wheel.

From the relay, a GRND wire should run up the steering column and hook to the horn button ring switch beneath the steering wheel.

A simple ground wire between the body and the GRND on the relay should validate the relay and horns are operational.

If they are, then the problem is the in GRND wire. A test light can be used to figure out where the problem lies. You can poke the GRND wire, right after it exits the steering box with, with the alligator clip of the test light connected to the non-ground terminal on the battery and then have someone press the horn button. If the test light illuminates, then the problem is between between that point in the wire and the relay. If it doesn't illuminate, then the problem is either the wire portion in the steering column, or the corrosion where the horn ring switch is. On my car the horn ring contact plate was rusty and had to be cleaned to get my horn operational again.

On the horn wire running through the steering column, is it clamped inside anywhere other than at the top? Mine is rotted away at the bottom where it exits the steering box and I'm wondering if it's possible to use the old wire to fish a new one through?

Should be soldered to the contact disc at the top but nothing else. The hole thru the exit tube in shaft at the bottom is relatively small so definitely easier to attach a new wire and use the old to pull it thru if feeding from the top. Make sure the connection is very thin -- not much wider than the diameter of wire. If just feeding a new wire only you can usually push it thru from the bottom OK and then solder to the disc once it exits the top.

Yes, I understand and agree with every point you made. This Packard has a relatively new wiring harness so there is a splice between the steering box ground wire from the horn ring and the new harness wire going to the horn relay ground terminal. The wire opening is in the harness part, because when I undid the splice and jumpered from the old ground wire from the steering box to the relay ground terminal the horns work great. Still can't imagine how the ground wire in the harness separated?

Still can't imagine how the ground wire in the harness separated?

Neither can I. With that relatively short distance, there should be no need for a splice in the loom. Should be a bullet or Douglas type connector about 6" from the steering box joining the wire from steering wheel to the loom. The only place that particular wire then goes is to the relay so they certainly should have been able to do it in one piece.

If it has regular terminal connectors, wonder if there is a poor crimp or solder connection at one end and it has developed corrosion between the terminal and wire.

Yes, I first cleaned the relay ground terminal and wire lug. Even removed the electrical tape from around the lug to be sure the ground wire was properly soldered, it was. As you say, the ground wire in the harness is only about 2 feet long. Both the ground and hot wires for the horns come out of the main harness at a right angle, my guess would be the break is there? Would like to identify the exact location of the break but would have to cut open the harness. Even thought of pulling a new wire attached to the bad wire through the harness, but with the sharp exit angle and the fact the wire maybe completely separated I don't think that would work?