Horns

[Dave Larnder]

Hi TR-ers.

 

Yesterday I found out that one of the horns was not working, so out came the workshop manual and a quick read to find out what the gap in the points should be, but nowhere does it say. So out came the holding down bolts, as it was not possible to remove the dome with the rad support and a lot of wiring bullet connectors. Dangling down on its supply wires, I took off the dome and then the sheet metal hoop that the dome screws into,and found no gap at all.

However on removing the hoop, It touched something, and a small spark appeared ( I had forgotten to isolate the battery) so I turned off the power, and quickly bolted the horn to the chassis ( according to the manual, the horn won´t work if it is not bolted down tightly). To see that no damage had ocured or fuse blown, I reconnected and sounded the horns, and to my surprise, it worked again, so I reversed all the steps and job done.

The question is: ¿What should that gap be?

 

Dave

Edited October 14, 2015 by Dave Larnder

[Andrew Smith]

Dave,

 

I think something is missing................

 

But to answer your question, yes I get one from time to time!

 

Cheers

Andrew

[Mark69]

Is that when you reminisce about your time spent with Linda Lusardi .

[mike3md]

Hi Dave,

 

Getting back to your query, after the musings above, this may help (apologies for the source):

 

http://www.vintagemg.com/articlepdfs/thorns1-2.pdf

 

Mike

[BlueTR3A-5EKT]

Hi Dave,

 

Getting back to your query, after the musings above, this may help (apologies for the source):

 

http://www.vintagemg.com/articlepdfs/thorns1-2.pdf

 

Mike

Good article. especially the size of the spanners

 

Same info is in the original service manual (pt no 502602) page 29 - 31 of the Electrical Equipment Section.

 

Peter W

[Dave Larnder]

Good article. especially the size of the spanners

 

Same info is in the original service manual (pt no 502602) page 29 - 31 of the Electrical Equipment Section.

 

Peter W and Mike

 

 

 

Thanks for the info. It was pages 29-31 that I referred to but as I said there is nothing given on the points gap.

 

Mike.

The attachment was very interesting and I shall download the pages for record, however the first few were as per the manual, but I did appreciate the exploded view and those huge spanners Peter.But still no info on that gap in the top points! maybe there isn´t one! only the 0.0055 on the diaphragm, but that maybe the only one.

Thanks

 

Dave

[Lebro]

Logicaly there should not be a gap - if there was the horn would do nothing, as there would be no current flow.

A gap only occurs once the horn has started - the first movement of the diaphram opens the points , thus stopping the current flow, so it goes back again - and so on. The trick is to adjust the pressure on the points to get a consistant blast from the horn (warn the neigbours !)

 

Bob.

[Alan Young]

Hi Dave

 

I have just found my Lucas Windtone Horn, 'Instructions for fitting and Maintenance'

 

Models WT 614, WT 28, and WT 29

 

Adjustment of Horns reads,

 

Adjustment can be made by resetting the contact breaker.

 

Slacken the the lock nut on the the fixed contact and rotate the adjusting nut until the contacts are just separated [ indicated by the horn failing to sound ].

 

hope this helps

 

Alan

[Dave Larnder]

Thanks Alan, that is what the manual said, but nothing about closing it down again.

Bob

I gathered that, so I was about to clean that push rod and lightly oil it when my spark occurred, and it worked again, so I left it. If it works - don´t fiddle with it.

 

Dave

[Lebro]

If the points are set too close then they will not open = lots of current, but no sound, if not close enough then no current = no sound.

I would suggest the optimum stting is half way between the settings at which the above occurs.

 

So unwind the setting till points are open, press horn button, & wind in adjuster till horn starts making noises, note the position of adjuster, continue to wind in(counting the turns) till noise stops, release horn button (quick), finaly wind back out half the number of turns, lock.

 

Bob.