• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

Question three - horn - electricery

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
So, My horn has been flatulant lately - I do have it on a relay but, that seems irrelevant to my question. Now, when I press the horn, nothing happens except I hear the relay click. If I disconnect one horn the other works perfectly. If I reverse it the other horn works perfectly. They are hooked up with the same power wire - in parallel not in series and likewise they have the same ground wire.

My brother in law the electrician looked at it at Easter and said I needed a new battery - I put in the new battery tonight and nothing changed.

What am I missing, any thoughts? (and yes I can just use one horn but I don't want to)

thanks!
 

smaceng

Jedi Knight
Country flag
Offline
Horn problems are usually due to poor grounds. Your car may have some devil in it as the symptoms don't make it obvious was is causing it.
 

Gliderman8

Yoda
Gold
Country flag
Offline
What happens when you temporarily bypass the relay and apply power? Just wondering if the contacts in the relay are pitted.
 
OP
JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
What happens when you temporarily bypass the relay and apply power? Just wondering if the contacts in the relay are pitted.

same thing - and I have swapped out the relay - though admittedly not the harness
 

Bayless

Yoda
Silver
Country flag
Offline
Sure sounds like too much resistance somewhere in the circuit. Most likely the ground but could be in the harness. if not the ground, try a jumper straight from the battery to the relay. If that doesn't work then another jumper from the relay to the horns. One of these should at least tell you where the gremlin lies.
 

SD Bugeye

Jedi Warrior
Country flag
Offline
You say you have it on a relay could be the points can't pass enough ampere to satisfy both bigger or separate relays?
 

Gerard

Luke Skywalker
Offline

Gerard

Luke Skywalker
Offline
If you have the horns with 2 spade terminals, make sure you using the contact that goes to ground. The purple with black tracer are the ground circuit wires.
 
OP
JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
I am still perplexed by this. I tore out the whole relay and my manufactured grounds last night - reinstalled it according to the factory and, no change. So, for now one horn and see what happens.
 

AndriesS

Freshman Member
Offline
if you have a test light or multimeter I would suggest connecting them to the horn wires, As per your case disconnect the one horn and check on disconnected horn wires, light should go on show 12V when horn is pressed which indicates wires are intact, now connect horn and see if you still get 12V or the light goes one, if not it means that you have serious resistance on the horn circuit. Then look at the wiring providing power to the high amp side of the relay.


Since monty etc has been quoted I can throw this one in, your 2 horns are out of phase and thus are cancelling each other out and that's why you don't hear a thing.

I assume you have pt 85 and 86 linked to your horn button and 12V and then 30 to 12V via a fuse and 87 to the positive on the horns

I'll also check if one of the horn connectors does not bleed to earth, i.e. measure the resistance between the spade connector and the mounting bolt, they should all have infinite, if not and one has 0 impedance then that is the spade that should be connected to earth.
 
OP
JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
Thanks! this is helpful - will take a look. The relay is now gone but, will see what I can see. I am just heading out of town but, hope to drive to my first show Sunday. BTW, where in SA are you? One of my dearest friends is from Stellenbosch and another friend from Pretoria and yet another Cape Town.
 
Similar threads
Thread starter Title Forum Replies Date
T Brake Question part three Triumph 8
G Three Bears Plug Question Triumph 6
AngliaGT MGB-GT Extremely Dumb Question - Distributor Hose - SOLVED! MG 3
Lin Ignition timing question Spridgets 2
Lin Oil sump sealant question Spridgets 0
D TR2/3/3A Another Carb question. Triumph 22
Sarastro TR4/4A Differential setup question Triumph 12
T TR2/3/3A Question on old radio from my TR3 Triumph 9
T TR2/3/3A TR3A rack & pinion conversion question - solution for horn & directional lever Triumph 2
H GT6 ...and a basketweave seat cover question Triumph 2
Lin Heater water valve question Spridgets 2
RJS General TR Wire Wheel Spline Question Triumph 3
Got_All_4 TR6 Distributor Gear Mounting Question Need End Float Washer Triumph 4
D TR2/3/3A rearmost fuel line question Triumph 5
jlaird MGB This weeks werd question regarding steering racks. MG 3
nichola TR6 Question on new wiring harness Triumph 6
JPSmit Today's question - vacuum advance Spridgets 2
B Rotisserie question Spridgets 4
RJS TR4/4A TR4A Seat Upholstery - Piping Question Triumph 7
J TR6 73 TR6 Temp Gauge Wiring Question Triumph 6
JPSmit Electricity question Restoration & Tools 3
71TR6 TR2/3/3A TR3A Scuttle Rim Question Triumph 4
JPSmit todays's job - and a question Spridgets 25
Y TR6 SU HS6 question Triumph 1
B TR6 TR6 1976 Clutch Choice Question Triumph 3
P '58 XK150 Dynalite Alternator swap question Jaguar 0
glemon TR2/3/3A Crankshaft Question Triumph 3
JPSmit Fuel line - gas tank question Restoration & Tools 5
Lin New Forum Upgrade Question Austin Healey 8
steveg TR6 Question - which bolt for heater return pipe bracket Triumph 3
jlaird MGB Strange daily question. MG 10
F TR2/3/3A Floor pan question Triumph 16
F TR2/3/3A Bumper bracket to frame question Triumph 7
Simmo General Tech Electrical question Triumph 4
T TR4/4A Surrey top question Triumph 18
JPSmit Vauxhall question - I know, weird eh?! Lotus 6
S TR2/3/3A C39/C40 question Triumph 7
nichola TR6 Seat belt reinforcing plate question Triumph 15
J TR6 TR6 Differential Rebuild question Triumph 6
D Tri carb: order of installation question. Austin Healey 5
C MGA Mirror question MG 0
JPSmit Todays question - wiring Spridgets 14
P TR6 1970 TR6 Timing Question Triumph 2
Lin Another Trafficator/Control Head Question Austin Healey 10
Lin Brake hard line question Austin Healey 4
J TR6 Vacuum Retard question Triumph 1
tahoe healey Dumb carb question Austin Healey 23
VooDooDaddy63 Basic E-Type Question: Fasteners - Metric or SAE or ...? Jaguar 15
J TR6 Moss HS6 SU conversion kit question Triumph 4
Lin "A" Pillars: A Question Austin Healey 8

Similar threads

Top