Posted By |
Discussion Topic:
Horn relay needed?
|
|
supereal |
05-01-2010 @ 8:46 AM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
The horn relay was likely added when the substitute horns were installed. The old style horns, such as on your '36, didn't need a relay, but the later horns certainly do, as they draw very heavy current, and would destroy the horn button grounding circuit in short order. Next to the starter and headlights, the horns draw the most current in the car. Without the relay, the "buzz" caused by the horns at the button or ring would be a real jolt, as well. Even so, some horn circuits rely on a resistive wire to eliminate that shock generated by the horn coils.
|
TomO |
05-01-2010 @ 7:08 AM
|
|
|
Senior
Posts: 7258
Joined: Oct 2009
|
Your horns receive their ground through the horn button. Disconnect the yellow and green wire from the horn and use a multimeter set on Ohms. Connect one lead to the yellow and green wire and the other to the ground strap. Press the horn button and your meter should read less than .05. If it is more, check the connection between the steering column and the chassis for the same reading. You could also have low voltage at the horns. Check the voltage drop between the battery and the horns by connecting the negative or common lead of your meter to the battery NEG terminal and the positive or + lead to the yellow wire on the horns. When the horn button is pressed, you should have less than .1 reading on your meter.
Tom
|
ole_Bill |
05-01-2010 @ 5:49 AM
|
|
|
New Member
Posts: 165
Joined: Dec 2009
|
Interestingly enough, when I got the car it had a horn relay mounted on the firewall but no horns. I bought a horn on ebay and tested it prior to installation - it worked on the bench. I have also replaced all of the major wiring harnesses on the car including dash, lights and horns. I did not replace wires in the steering column. The light switch works as designed and I know the horn button is at least making contact. When I was installing the new harnesses, I found the bulb at the base of the steering column to be full of grease. I cleaned it up and put it back and the car hasn't been driven since, so I don't think that is the problem either. All the bullet contacts fitted very snugly but I can go back and spray them to see if that increases conductivity. For now, I'm thinking the poor grounds on the car (which have shown up on several other problems) are probably the cause. Thanks for the help, I'll post what I find.
|
37RAGTOPMAN |
04-30-2010 @ 5:40 PM
|
|
|
Senior
Posts: 1965
Joined: Oct 2009
|
sounds to me like you have dirty contact on the connections,on the wiring inline bullets,trace the wiring looking for any dirty contacts,you can also, check the bottom of steering column horn contact also do you have one or 2 horns ? I would first remove the horn and bench test with a good 6volt battery,and make sure the horn is good, then go on to other tests, the horn might just need a cleaning and a ajustment, just spraying with CRC electric motive cleaner might help on the contacts, make sure you have good grounds, you do not need a horn relay,it did not need one for the last 74 years, if the horn is defective a relay will not help, let hear how you made out, KEEP ON TRUCKIN,37RAGTOPMAN was it working before ? did it go on the blink all of a sudden ?
|
ole_Bill |
04-30-2010 @ 12:44 PM
|
|
|
New Member
Posts: 165
Joined: Dec 2009
|
The wiring diagrams for my '36 Tudor Sedan do not show a horn relay, however when I press the horn button I get only a tiny squeek as the button goes in and again when it is released. Does this mean I need a relay...and if so, how is it wired in?
|