• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A Horn Button TR3 Trafficator; Bad ground?

Share this page

F

Frank_D

Senior Member
Country flag
Offline
I have a grounding problem with the horns on my '59 TR3A. Horns will not sound or are very weak when depressing the horn button. I unplugged the trafficator wiring lead from the horn button, inserted a small jumper into the harness and when I put it to ground I got great sound out of both my horns. Before I remove the trafficator, any advice. How is the grounding ring in the trafficator connected to ground? Could my problem be there or in the actual horn button. Any advice is most appreciated.

Frank D............
 
In my experience, the problem is more likely to be the button contacts themselves. The horns are very inductive loads, so there is a spark at the contacts every time the button is released. Each spark removes a tiny amount of metal, so over time the contacts wear away, become rough and pitted.

One solution to this is to add a horn relay (after cleaning up the contacts).

I'm not sure which path the current follows, but both the stator tube and steering column are pretty well grounded at the steering box, so either one would do.
 
Hornbuttonrepair_3-1.jpg

Hornbuttonrepair_1.jpg

Hornbuttonrepair_2.jpg

<span style="font-size: 11pt"><span style="color: #003300">The photos show what results after 40+ years of beeping the horn(s)To simplify it,he right set of contacts is the ground side (I believe thru the stator tube), the burnt left side is the load side. You don't have to take the trafficator very far apart to access the ring and contacts. (DISCONNECT THE BATTERY!)Loosen the 3 set screws holding the trafficator in place. Pull the trafficator out of the stator tube far enough to access the back.Just remove the 3 screws shown in the photo, Clean the contacts, raise the burnt side so all contacts are the same level, Clean the ring as best you can (get the dirt out of the holes!) and re-assemble. Set the trafficator back in the stator tube a couple of inches, reconnect the battery & test. Should work fine. If it does, buy and install a horn relay. If you aren't sure about how to go about the relay, PM me & I'll send you complete instructions, or do a search...I think installation has been covered on a earlier thread.
Frank </span></span>
 
Back
Top